Flexible reduced pressure treatment appliance

ABSTRACT

A wound treatment appliance is provided for treating all or a portion of a wound. In some embodiments, the appliance comprises an impermeable flexible overlay that covers all or a portion of the wound for purposes of applying a reduced pressure to the covered portion of the wound. In other embodiments, the impermeable flexible overlay comprises suction assistance means, such as channels, which assist in the application of reduced pressure to the area of the wound and removal of exudate from the wound. In other embodiments, the wound treatment appliance also includes a vacuum system to supply reduced pressure to the wound in the area under the flexible overlay. In yet other embodiments, the wound treatment appliance also includes wound packing means to prevent overgrowth of the wound or to encourage growth of the wound tissue into an absorbable matrix comprising the wound packing means. In still other embodiments, the appliance may include a suction drain. In other embodiments, the appliance may include a collection chamber to collect and store exudate from the wound. In yet other embodiments, a suction bulb may be used to provide a source of reduced pressure to an impermeable overlay that covers all or a portion of the wound. Finally, methods are provided for using various embodiments of the wound treatment appliance.

CROSS REFERENCES TO OTHER APPLICATIONS

This application claims the benefit of U.S. provisional application No.60/559,727, filed on Apr. 5, 2004, and is also a continuation-in-part ofU.S. patent application Ser. No. 11/064,813, filed on Feb. 24, 2005. Thefull disclosures of this provisional application and this nonprovisionalapplication are incorporated herein by reference.

BACKGROUND

The present invention generally relates to treatment of wounds, and morespecifically to an improved apparatus and method for treating all or aportion of a wound on a body by applying reduced pressure to the portionof the wound for which treatment is desired. In this context, the terms“wound” and “body” are to be interpreted broadly, to include any bodypart of a patient that may be treated using reduced pressure.

The treatment of open or chronic wounds that are too large tospontaneously close or otherwise fail to heal by means of applyingreduced pressure to the site of the wound is well known in the art. Onesuch system is disclosed in U.S. patent application Ser. No. 10/652,100,which was filed by the present inventor with the U.S. Patent andTrademark Office on Aug. 28, 2003. The disclosure of this U.S. patentapplication is incorporated herein by reference. Another system isdisclosed in a U.S. patent application entitled “Improved ReducedPressure Wound Treatment Appliance,” which was filed by the presentinventor with the U.S. Patent and Trademark Office on or about Dec. 30,2004. The disclosure of this U.S. patent application is alsoincorporated herein by reference.

Reduced pressure wound treatment systems currently known in the artcommonly involve placing a cover that is impermeable to liquids over thewound, using various means to seal the cover to the tissue of thepatient surrounding the wound, and connecting a source of reducedpressure (such as a vacuum pump) to the cover in a manner so that anarea of reduced pressure is created under the cover in the area of thewound. However, the covers currently known and used in the art have anumber of disadvantages. For example, in one version they tend to be inthe form of a flexible sheet of material that is placed over the woundand sealed to the surrounding tissue using an adhesive, adhesive tape,or other similar means. As tissue swelling in the area of the wounddecreases during the healing process, the adhesive may begin to stretchthe surrounding tissue, as well as tissue within the wound, resulting indiscomfort and pain to the patient. This may necessitate more frequentcover changes, increasing the time medical staff must expend in treatingthe wound. This additional time, of course, also tends to increase theexpense involved in treating the wound. In addition, these types ofcovers can typically only be used where there is normal tissue adjacentto the wound to which the adhesive seal can be attached. Otherwise, theseal must be made in a portion of the area of the wound, and exudatefrom the wound tends to break the seal so that reduced pressure cannotbe maintained beneath the wound cover. Thus, such covers (and many othercovers requiring adhesive seals) may typically only be used to treat anentire wound, as opposed to only a portion of a wound. Further, theadhesive seal creates discomfort for the patient when the sheet cover isremoved. In other versions, the covers tend to be rigid or semi-rigid innature so that they are held away from the surface of the wound. Inthese versions, the covers are sometimes difficult to use because theshape and contour of the patient's body in the area of the wound do notreadily adapt to the shape of the cover. In such cases, additional timeis required for the medical staff to adapt the cover for its intendeduse. This also increases the expense of wound treatment. In addition, itis also often necessary to use an adhesive, adhesive tape, or othersimilar means to seal the rigid or semi-rigid cover to the tissuesurrounding the wound. In these instances, the same disadvantagesdiscussed above with respect to the first version also apply to thisversion as well. In still other cases, the rigid and semi-rigid coversmust be used with padding in the area where the cover is adjacent to thepatient to prevent the edges of the cover from exerting undue pressureon the tissue surrounding the wound. Without the padding, the patientmay experience pain and discomfort. The additional padding, which maymake the cover itself more expensive, may also take a greater amount oftime to place on the patient for treatment purposes. These covers mayalso have the problem of placing tension on the surrounding tissue asthe swelling in the area of the wound decreases during the healingprocess. In yet another version, covers are constructed of combinationsof flexible materials and rigid materials. In these versions, a flexiblemember, such as a flexible sheet, is typically supported by a rigid orsemi-rigid structure that is either placed between the flexible memberand the wound or in the area above and outside the flexible member. Ineither case, the flexible member must usually be sealed to the tissuesurrounding the wound using an adhesive, adhesive tape, or other similarmeans. This seal creates the same problems described above. In addition,the same problems described above with respect to rigid and semi-rigidstructures are also often present. In all of the versions describedabove, it may be difficult to tell if reduced pressure in the area ofthe wound under the cover has been lost because the cover itself doesnot generally provide a visual clue of such loss.

Therefore, there is a need for a reduced pressure wound treatment systemthat has a means to enclose all or a portion of a wound without the needfor an adhesive seal. There is also a need for such enclosing means tobe flexible, so that it adapts to changing shapes and contours of thepatient's body as wound healing progresses. Further, there is a need foran enclosing means that is adaptable to a wide variety of patient bodyshapes and contours. There is also a need for an enclosing means that issimple to apply to the patient's body, and simple to remove from thepatient's body. Such enclosing means would also take less time to applyand remove, reducing the expense involved in wound treatment. There isalso a need for an enclosing means that is relatively inexpensive, whilemeeting the needs described above. In addition, there is a need for anenclosing means that may be used within the wound (or a portionthereof), without the need to seal the enclosing means to normal tissuesurrounding the wound. Further, there is a need for an enclosing meansthat flexes with movement of the portion of the body surrounding thewound, without the need for an adhesive seal or rigid or semi-rigidstructure. Finally, there is a need for an enclosing means that providesa visual clue of loss of reduced pressure in the area of the wound underthe enclosing means.

SUMMARY

The present invention is directed to a reduced pressure wound treatmentappliance and methods that satisfy the needs described above. Asdescribed in greater detail below, they have many advantages overexisting reduced pressure wound treatment apparatus and methods whenused for their intended purpose, as well as novel features that resultin a new reduced pressure wound treatment appliance and methods that arenot anticipated, rendered obvious, suggested, or even implied by any ofthe prior art apparatus or methods, either alone or in any combinationthereof.

In accordance with the present invention, a wound treatment appliance isprovided for treating all or a portion of a wound by applying reducedpressure (i.e., pressure that is below ambient atmospheric pressure) tothe portion of the wound to be treated in a controlled manner for aselected time period in a manner that overcomes the disadvantages ofcurrently existing apparatus. The application of reduced pressure to awound provides such benefits as faster healing, increased formation ofgranulation tissue, closure of chronic open wounds, reduction ofbacterial density within wounds, inhibition of burn penetration, andenhancement of flap and graft attachment. Wounds that have exhibitedpositive response to treatment by the application of negative pressureinclude infected open wounds, decubitus ulcers, dehisced incisions,partial thickness burns, and various lesions to which flaps or graftshave been attached.

In a first aspect of a first version of the present invention, the woundtreatment appliance is comprised of an impermeable flexible overlay andreduced pressure supply means, which are described in more detail belowand are used to connect the flexible overlay to a reduced pressuresupply source that provides a supply of reduced pressure to the flexibleoverlay. In this first aspect of the first version of the invention, theflexible overlay is adapted to be placed over and enclose all or aportion of a wound on the surface of the body of a patient. The flexibleoverlay is also adapted to maintain reduced pressure under the flexibleoverlay in the area of the wound. The flexible overlay collapses in theapproximate direction of the area of the wound to be treated whenreduced pressure is supplied to the volume under the flexible overlay inthe area of the wound. This collapse causes the formation of anapproximately hermetic seal (described in more detail below) between theflexible overlay and the body in the area of the wound. In someembodiments of this first aspect of the first version of the invention,the flexible overlay is further comprised of an interior surface facingthe area of the wound to be treated, wherein the surface area of theinterior surface is greater than the surface area of the portion of thebody to be enclosed by the flexible overlay. In other embodiments ofthis first aspect of the first version of the invention, the flexibleoverlay is further comprised of a bottom portion having an approximatelyelongated conical shape with an approximately elliptically-shaped openend at the base of the elongated conical bottom portion. In theseembodiments, the approximately elliptically-shaped open end at the baseis sized to be placed over and enclose the area of the wound to betreated. In yet other embodiments of this first aspect of the firstversion of the invention, the flexible overlay (as opposed to only thebottom portion thereof) has an approximately elongated conical shapehaving an approximately elliptically-shaped open end at its base. Inthese embodiments, the approximately elliptically-shaped perimeter ofthe open end at the base of the flexible overlay is positioned over allor a portion of the wound on the surface of the body. In some of theseembodiments, the flexible overlay further comprises a port locatedapproximately at the apex of the elongated conically-shaped flexibleoverlay. In these embodiments, the reduced pressure supply means isoperably connected to the port. In yet other embodiments of this firstaspect of the first version of the invention, the flexible overlay iscomprised of at least three cover portions, each of such cover portionsbeing approximately triangular in shape. One point of each of the atleast three triangular-shaped cover portions are joined to form an apexof the flexible overlay and one side of each at least threetriangular-shaped cover portions adjacent to the apex is joined to anadjacent side of another of such at least three triangular-shaped coverportions so that the bases of the at least three triangular-shaped coverportions form an opening sized to be placed over and enclose the area ofthe wound to be treated. In some of these embodiments, the flexibleoverlay is further comprised of a port located approximately at the apexof the flexible overlay and the reduced pressure supply means isoperably connected to the port. In yet other embodiments, the flexibleoverlay may be cup-shaped. In still other embodiments of this firstaspect of the first version of the invention, at least one fold forms inthe surface of the flexible overlay when it collapses, so that fluidsaspirated by the wound flow along the at least one fold to the reducedpressure supply means, where they are removed from the flexible overlayby means of the reduced pressure supply means cooperating with thereduced pressure supply source. In other embodiments, the flexibleoverlay is further comprised of suction assist means, which assist inthe application of reduced pressure to the area of the wound and removalof exudate from the wound. In some of these embodiments, the suctionassist means may be channels disposed in, or raised portions disposedon, the surface of the flexible overlay. In other embodiments, theappliance further comprises supplemental sealing means, which aredescribed in more detail below, to form a seal between the flexibleoverlay and the body in the area of the wound. In yet other embodiments,the appliance further comprises a suction drain and suction drainconnecting means, which are described in more detail below, to operablyconnect the reduced pressure supply means to the suction drain so thatthe suction drain is in fluid communication with the reduced pressuresupply means and reduced pressure is supplied to the volume under theflexible overlay in the area of the wound by means of the suction drain.The suction drain extends from the reduced pressure supply means intothe volume under the flexible overlay in the area of the wound.

In a second aspect of the first version of the present invention, thewound treatment appliance is comprised of a wound treatment device and avacuum system. In this second aspect of the first version of theinvention, the vacuum system is further comprised of a reduced pressuresupply source that provides a supply of reduced pressure and reducedpressure supply means to operably connect the wound treatment device tothe reduced pressure supply source, so that the volume under the woundtreatment device in the area of the wound is supplied with reducedpressure by the reduced pressure supply source. In various embodimentsof this second aspect of the first version of the invention, the woundtreatment device and the reduced pressure supply means may generallyhave substantially the same structure, features, characteristics andoperation as the appliance described above in connection with the firstaspect of the first version of the invention.

In some embodiments of this second aspect of the first version of theinvention, the reduced pressure supply source is comprised of a vacuumpump. In some of these embodiments, the reduced pressure supply sourcefurther comprises a control system for the vacuum pump, wherein thecontrol system may control at least the level of suction produced by thevacuum pump or the rate of fluid flow produced by the vacuum pump, orany combination of rate of suction and rate of fluid flow of the vacuumpump. In other embodiments, the reduced pressure supply source furthercomprises a filter operably positioned between the vacuum pump and thereduced pressure supply means. In these embodiments, the filter preventsthe venting of and contamination of the vacuum pump by micro-organismsaspirated from the wound or fluids aspirated from the wound or both. Inyet other embodiments, the vacuum pump is comprised of a portable vacuumpump. In still other embodiments of this second aspect of the firstversion of the invention, the reduced pressure supply means is comprisedof flexible tubing. In other embodiments, the reduced pressure supplymeans is further comprised of a collection system that is operablypositioned between the wound treatment device and the reduced pressuresupply source. In some of these embodiments, the collection systemcomprises a container to receive and hold fluid aspirated from the woundand pressure halting means to halt the application of reduced pressureto the wound when the fluid in the container exceeds a predeterminedamount. In other embodiments of this second aspect of the first versionof the invention, the reduced pressure under the flexible overlay in thearea of the wound is in the range from approximately 20 mm of Hg belowatmospheric pressure to approximately 125 mm of Hg below atmosphericpressure. In yet other embodiments, the reduced pressure is applied in acyclic nature, the cyclic nature providing alternating time periods ofapplication of reduced pressure and without application of reducedpressure. In some embodiments of this second aspect of the first versionof the invention, the wound treatment appliance further comprises tissueprotection means, which are described in more detail below, to protectand strengthen the body tissue that is adjacent to the flexible overlayat the wound site. In some of these embodiments, the tissue protectionmeans is a hydrocolloid material.

In a third aspect of the first version of the invention, the woundtreatment appliance is comprised of a wound treatment device, a vacuumsystem, and wound packing means, which are described in more detailbelow, that are positioned between the wound treatment device and theportion of the wound to be treated. In various embodiments of this thirdaspect of the first version of the invention, the wound treatment deviceand the vacuum system may generally have substantially the samestructure, features, characteristics and operations as the woundtreatment device and the vacuum system, respectively, described above inconnection with the second aspect of the first version of the invention.In this third aspect of the first version of the invention, the flexibleoverlay of the wound treatment device is placed over all or a portion ofthe wound and the wound packing means when the flexible overlay ispositioned on the surface of the body at the wound site. In someembodiments of this third aspect of the first version of the invention,the wound packing means is comprised of absorbent dressings, antisepticdressings, nonadherent dressings, water dressings, or combinations ofsuch dressings. In some of these embodiments, the wound packing means ispreferably comprised of gauze or cotton or any combination of gauze andcotton. In still other embodiments, the wound packing means is comprisedof an absorbable matrix adapted to encourage growth of the tissue in thearea of the wound under the flexible overlay into the matrix. Theabsorbable matrix is constructed of an absorbable material that isabsorbed into the epithelial and subcutaneous tissue in the wound as thewound heals. Because of the absorbable nature of the absorbable matrix,the matrix should require less frequent changing than other dressingtypes during the treatment process. In other circumstances, the matrixmay not need to be changed at all during the treatment process. In someof these embodiments, the absorbable matrix is comprised of collagen orother absorbable material. In some embodiments of this third aspect ofthe first version of the invention, the appliance further comprises asuction drain and suction drain connecting means, which are described inmore detail below, to operably connect the reduced pressure supply meansto the suction drain so that the suction drain is in fluid communicationwith the reduced pressure supply means and reduced pressure is suppliedto the volume under the impermeable flexible overlay in the area of thewound by means of the suction drain. In these embodiments, the suctiondrain extends from the reduced pressure supply means into the volumeunder the impermeable flexible overlay in the area of the wound. In someof these embodiments, the suction drain is further comprised of a distalend portion and the distal end portion has at least one perforation inthe surface thereof. In some of these embodiments, the distal endportion of the suction drain is positioned within the interior volume ofthe wound packing means.

In a fourth aspect of the first version of the invention, the woundtreatment appliance is comprised of a wound treatment device and avacuum system. In various embodiments of this fourth aspect of the firstversion of the invention, the wound treatment device is comprised of animpermeable flexible overlay and a seal. The impermeable flexibleoverlay is sized to be placed over and enclose the area of the wound tobe treated and is adapted to maintain reduced pressure in the area ofthe wound to be treated. The seal seals the impermeable flexible overlayto the body in the area of the wound in a manner so that reducedpressure is maintained under the impermeable overlay in the area of thewound to be treated. In addition, in the various embodiments of thisfourth aspect of the first version of the invention, the vacuum systemis comprised of a suction bulb, which may (but not necessarily) providea source of reduced pressure, and reduced pressure supply means, whichare described in more detail below, to operably connect the impermeableflexible overlay to the suction bulb, so that the area of the woundunder the impermeable flexible overlay may be supplied with reducedpressure by the suction bulb. In some embodiments of this fourth aspectof the first version of the invention, the flexible wound cover may becomprised of a flexible overlay that has substantially the samestructure, features, characteristics and operation as the flexibleoverlay described above in connection with the first aspect of thisfirst version of the invention. In some embodiments of this fourthaspect of the first version of the invention, the suction bulb isfurther comprised of an inlet port and an outlet port, wherein the inletport is operably connected to the reduced pressure supply means, and thevacuum system further comprises an exhaust tubing member operablyconnected to the outlet port. In some of these embodiments, the vacuumsystem further comprises an exhaust control valve operably connected tothe exhaust tubing member. In other embodiments, the vacuum system isfurther comprised of a filter operably connected to the exhaust tubingmember, which prevents the venting of micro-organisms aspirated from thewound or fluids aspirated from the wound or both. In yet otherembodiments, the vacuum system is further comprised of a supplementalvacuum system that is operably connected to the exhaust tubing member.In these embodiments, the supplemental vacuum system may generally havesubstantially the same structure, features, characteristics andoperation as the vacuum system described above in connection with thesecond and third aspects of the first version of the invention.

A fifth aspect of the first version of the present invention discloses amethod of treating a wound on a body. In one embodiment of this fifthaspect of the first version of the invention, the method comprises thefollowing steps. First, positioning an flexible overlay on the body overthe area of the wound to be treated, wherein the flexible overlay issized to be placed over and enclose the area of the wound to be treatedand adapted to maintain reduced pressure in the area of the wound to betreated. Second, operably connecting the flexible overlay with a vacuumsystem for producing reduced pressure in the volume under the flexibleoverlay in the area of the wound to be treated. Third, collapsing theflexible overlay in the approximate direction of the wound when reducedpressure is supplied to the volume under the flexible overlay in thearea of the wound so that an approximately hermetic seal (described inmore detail below) is formed between the impermeable flexible overlayand the body in the area of the wound. Fourth, maintaining the reducedpressure until the area of the wound being treated has progressed towarda selected stage of healing. In other embodiments of this fifth aspectof the first version of the invention, the method further comprises thestep of placing tissue protection means on the tissue of the body thatis to be approximately adjacent to the flexible overlay, such step beingperformed prior to positioning the flexible overlay over the area of thewound to be treated. The tissue protection means, which is described inmore detail below, protects and strengthens the tissue of the bodyadjacent to the flexible overlay at the wound site. In yet otherembodiments of this fifth aspect of the first version of the invention,the method further comprises the step of placing wound packing means(described in more detail above) between the wound and the flexibleoverlay in the area of the wound to be treated, such step beingperformed prior to positioning the flexible overlay over the area of thewound to be treated. In still other embodiments of this fifth aspect ofthe first version of the invention, the vacuum system is comprised of asuction bulb and the method further comprises the step of squeezing thesuction bulb to reduce its volume and then releasing the suction bulb,so that reduced pressure is produced in the volume under the flexibleoverlay in the area of the wound. In other embodiments of this fifthaspect of the first version of the invention, the reduced pressure underthe impermeable overlay in the area of the wound is in the range fromapproximately 20 mm of Hg below atmospheric pressure to approximately125 mm of Hg below atmospheric pressure. In still other embodiments ofthis fifth aspect of the first version of the invention, the reducedpressure is applied in a cyclic nature, the cyclic nature providingalternating time periods of application of reduced pressure and withoutapplication of reduced pressure.

As is illustrated in the detailed descriptions herein, the woundtreatment appliance of the present invention meets the needs discussedabove in the Background section. For example, in the preferredembodiment of a flexible overlay having a bottom portion with anapproximately elongated conical shape, the flexible overlay is placedover and encloses all or a portion of the wound. When the flexibleoverlay is enclosing all or a portion of the wound, the portions of theflexible overlay positioned adjacent to the surface of the body at thewound site are at (or can be deformed to be at) a relatively acute anglerelative to such surface of the body. When reduced pressure is appliedto the area under the flexible overlay, the flexible overlay is drawndownward, collapsing the flexible overlay in the approximate directionof the wound. As the flexible overlay collapses, the portions of theflexible overlay adjacent to the perimeter of the opening of theflexible overlay are drawn tightly against the surface of the body atthe wound site, thus forming an approximately hermetic seal. Referencesto an “approximately hermetic seal” herein refer generally to a sealthat is gas-tight and liquid-tight for purposes of the reduced pressuretreatment of the wound. It is to be noted that this seal need not beentirely gas-tight and liquid-tight. For example, the approximatelyhermetic seal may allow for a relatively small degree of leakage, sothat outside air may enter the volume under the flexible overlay in thearea of the wound, as long as the degree of leakage is small enough sothat the vacuum system can maintain the desired degree of reducedpressure in the volume under the flexible overlay in the area of thewound. In some uses where the collapsing flexible overlay may notproduce an approximately hermetic seal that is solely capable ofmaintaining the reduced pressure in the volume under the impermeableoverlay in the area of the wound, it may be necessary to providesupplemental sealing means, which are described in more detail below,and which are used to provide a seal between the portions of theflexible overlay and the body where the approximately hermetic seal isnot adequate. As a result, the flexible overlay is simple to apply tothe patient. There is also often no need for any other sealing means inmost cases, which means that there is usually no need for medical staffto take the time to make a separate seal. Even where the geometry of thesurface of the body surrounding the wound may require that supplementalsealing means be used to provide some limited assistance to ensure aseal, the amount of such assistance (such as by applying an adhesive) islimited, especially when compared to current covers in the art. Inaddition, as swelling of tissue at the wound site decreases, theflexible nature of the flexible overlay allows it to further deform toconform to the changing shape and contours at the wound site. Thisprevents the patient from being discomforted as the swelling decreases.It also reduces the need to change the covering over the wound ashealing progresses. This is generally not true in cases involvingflexible, semi-rigid and rigid covers that exist in the art. Forexample, even where semi-rigid and rigid covers do not utilize anadhesive seal and rely solely upon the reduced pressure to hold them inplace, they do not generally change shape enough to flex withsubstantial changes in the shape and contour of the surrounding bodysurface. Thus, they may not be appropriate for use with body portionsthat are subject to such changes, while the flexible nature of theflexible overlay, along with its increased surface area that can bendand flex, allow it to be used in such circumstances without the need foran adhesive seal. In the same way, the flexible overlay may generally beused for unusual geometries of the body at or surrounding the woundbecause of the overlay's flexible nature and relatively large surfacearea. In contrast, flexible sheets and semi-rigid and rigid covers mayrequire substantial modification and means to provide an adequate seal.In addition, such covers may require that the patient be partially orwholly immobilized during the treatment process to avoid movement in thearea of the body surrounding the wound to avoid breaking the seal. Andsuch covers must usually be sealed to normal tissue surrounding thewound. The flexible overlay, however, may be used within the perimeterof a wound in many cases because there is not typically a need to sealthe flexible overlay to normal tissue surrounding the wound. Further,because there is typically no need for an adhesive seal, removal of theflexible overlay merely requires removal of the reduced pressure fromthe area under the flexible overlay. It is thus simple to remove fromthe patient. For this reason, it will tend to reduce the time requiredof medical staff for wound treatment, which will also tend to reduce thecost of wound treatment. In addition, there is no pain and discomfortfor the patient when the flexible overlay is removed. Even if a limitedamount of supplemental sealing means (such as an adhesive) are requiredto provide a seal at a portion of the flexible overlay that is adjacentto the surface surrounding the wound, the reduced amount of supplementalsealing means will cause a corresponding reduction in the amount of suchpain and discomfort. Further, the preferred embodiments of the collapsedflexible overlay will have folds in its surface while in the collapsedstate, so that fluid aspirated by the wound may flow along the folds tobe removed from under the flexible overlay. In some embodiments, theflexible overlay is further comprised of suction assist means, whichalso assist in the application of reduced pressure to the area of thewound and removal of exudate from the wound. In some of theseembodiments, the suction assist means may be channels disposed in, orraised portions disposed on, the surface of the flexible overlay. Inaddition, if reduced pressure is lost under the flexible overlay, theflexible overlay will expand outward from the wound, providing a visualindication that reduced pressure has been lost. Finally, in itspreferred embodiments, the flexible overlay is relatively inexpensive tomanufacture, even though it meets the described needs.

In a first aspect of a second version of the present invention, thewound treatment appliance is comprised of a fluid impermeable flexibleoverlay, a collection chamber to receive and hold fluid aspirated fromthe wound, collection chamber attachment means to operably attach thecollection chamber to the flexible overlay, as described in more detailbelow, and reduced pressure supply means, which are described in moredetail below. In this first aspect of the second version of theinvention, the flexible overlay is adapted to be placed over and encloseall or a portion of the wound. In the various embodiments of this firstaspect of the second version of the invention, except as described inmore detail below, the flexible overlay has substantially the samestructure, features characteristics and operation as the flexibleoverlay described above in connection with the first aspect of the firstversion of the invention. In addition, in this first aspect of thesecond version of the invention, the reduced pressure supply means isused to operably connect the collection chamber to a reduced pressuresupply source that provides a supply of reduced pressure to thecollection chamber, so that the volume within the collection chamber andunder the impermeable overlay in the area of the wound to be treated aresupplied with reduced pressure by the reduced pressure supply source. Inthe various embodiments of this second version of the invention, exceptas described in more detail below, the reduced pressure supply means toconnect the reduced pressure supply source to the collection chamber inthe embodiments of this second version of the invention may havesubstantially the same structure, features, characteristics andoperation as the reduced pressure supply means described above inconnection with the first version of the invention.

In this first aspect of the second version of the invention, theflexible overlay is attached by collection chamber attachment means to acollection chamber that receives and holds fluid aspirated from thewound. In some embodiments, the collection chamber may be approximatelycylindrical in shape. In the various embodiments of this first aspect ofthe second version of the invention, the collection chamber attachmentmeans operably attaches the collection chamber to the flexible overlayin a manner so that the fluid and reduced pressure are permitted to flowbetween the collection chamber and the volume under the flexible overlayin the area of the wound. In some embodiments of this first aspect ofthe second version of the invention, the collection chamber ispositioned approximately adjacent to the impermeable flexible overlay onthe side of the impermeable flexible overlay opposite the wound and thecollection chamber attachment means is a rigid or semi-rigid connectingmember positioned between the collection chamber and the impermeableflexible overlay. In these embodiments, the connecting member has a porttherein that extends between the collection chamber and the flexibleoverlay. In embodiments where the flexible overlay is approximatelyelongated-conically shaped, the collection chamber and the collectionchamber attachment means may be positioned approximately at the apex ofthe flexible overlay on the side of the impermeable flexible overlayopposite the wound. In some embodiments, the collection chamber may beapproximately cylindrical in shape. In other embodiments, the collectionchamber attachment means may be further comprised of a flow controlmeans, which is described in more detail below, operably positionedbetween the collection chamber and the flexible overlay. In theseembodiments, the flow control means permit the fluid to flow from thevolume under the flexible overlay in the area of the wound into thecollection chamber, but not in the opposite direction. In some of theseembodiments, the flow control means may be comprised of a valve. In someof these embodiments, the valve may be comprised of a flapper-typevalve. In yet other embodiments, the collection chamber is positionedapproximately adjacent to the impermeable flexible overlay on the sideof the impermeable flexible overlay opposite the wound and thecollection chamber attachment means is comprised of a membrane. In theseembodiments, the membrane acts as a barrier separating the collectionchamber and the impermeable flexible overlay, so that the membrane actsas a portion of the surface of the collection chamber and a portion ofthe surface of the impermeable flexible overlay. In addition, themembrane has at least one port therein so that the volume within thecollection chamber is in fluid communication with the volume under theimpermeable flexible overlay in the area of the wound. In embodimentswhere the impermeable flexible overlay has an approximately conicalshape or approximately elongated conical shape, the impermeable flexibleoverlay may have a base end opening and a top end opening opposite thebase end opening. In these embodiments, the base end opening may have aneither approximately circular shape or approximately elliptical shapesized to be placed over and enclose the area of the wound to be treated.The top end opening may have either an approximately circular shape orapproximately elliptical shape. In these embodiments, the membrane issized to be of the same shape and size as the top end opening and themembrane is positioned so that it is attached to the entire perimeter ofthe top end opening and covers the entire top end opening. In someembodiments, the collection chamber may have an approximately conicalshape or approximately elongated conical shape with a chamber bottom endopening and a reduced pressure supply port positioned at the apex of thecollection chamber opposite the chamber bottom end opening. In variousembodiments, the chamber bottom end opening may have an eitherapproximately circular shape or approximately elliptical shape adaptedto be of approximately the same size and shape as the top end opening ofthe impermeable flexible overlay. In some of these embodiments, theperimeter of the chamber bottom end opening is attached to the membranein a manner so that the collection chamber is airtight, except for theport in the membrane and the reduced pressure supply port. The reducedpressure supply port operably connects the reduced pressure supply meansto the collection chamber. In some embodiments, the collection chamberattachment means is further comprised of flow control means operablyconnected with the at least one port, wherein the flow control meanspermits fluid aspirated from the wound to flow from the volume under theimpermeable flexible overlay in the area of the wound through the atleast one port to the collection chamber, but not in the oppositedirection. In some of these embodiments, the flow control means iscomprised of a valve. Preferably, this valve is comprised of aflapper-type valve.

In a second aspect of the second version of the present invention, thewound treatment appliance is comprised of a wound treatment device and avacuum system, which is further comprised of a reduced pressure supplysource that provides a supply of reduced pressure and reduced pressuresupply means to operably connect the wound treatment device to thereduced pressure supply source. In various embodiments of this secondaspect of the second version of the invention, except as describedbelow, the wound treatment device and the reduced pressure supply meansmay generally have substantially the same structure, features,characteristics and operations as the appliance described above inconnection with the first aspect of the second version of the invention.In these embodiments, the reduced pressure supply means operably connectthe wound treatment device to the reduced pressure supply source so thatthe volume within the collection chamber and under the wound treatmentdevice in the area of the wound is supplied with reduced pressure by thereduced pressure supply source.

In some embodiments of this second aspect of the second version of theinvention, the reduced pressure supply source is comprised of a vacuumpump. In some of these embodiments, the reduced pressure supply sourcefurther comprises a control system for the vacuum pump, wherein thecontrol system controls the operation of the vacuum pump. In otherembodiments, the reduced pressure supply source further comprises afilter operably positioned between the vacuum pump and the reducedpressure supply means. In these embodiments, the filter prevents theventing of and contamination of the vacuum pump by micro-organismsaspirated from the wound or fluids aspirated from the wound or both. Inyet other embodiments, the vacuum pump is comprised of a portable vacuumpump. In still other embodiments, the reduced pressure supply means iscomprised of flexible tubing. In other embodiments of this second aspectof the second version of the invention, the reduced pressure under theflexible overlay in the area of the wound is in the range fromapproximately 20 mm of Hg below atmospheric pressure to approximately125 mm of Hg below atmospheric pressure. In yet other embodiments, thereduced pressure is applied in a cyclic nature, the cyclic natureproviding alternating time periods of application of reduced pressureand without application of reduced pressure. In some embodiments of thissecond aspect of the second version of the invention, the woundtreatment appliance further comprises tissue protection means, which aredescribed in more detail below, to protect and strengthen the bodytissue that is adjacent to the flexible overlay at the wound site. Insome of these embodiments, the tissue protection means is a hydrocolloidmaterial. In still other embodiments, wound packing means, which aredescribed in more detail herein, are positioned between the woundtreatment device and the portion of the wound to be treated.

A third aspect of the second version of the present invention disclosesa method of treating a wound on a body. In one embodiment of this thirdaspect of the second version of the invention, the method comprises thefollowing steps. First, a wound treatment device is positioned on thebody over the area of the wound to be treated, wherein the woundtreatment device is comprised of an impermeable flexible overlay, acollection chamber, and collection chamber attachment means, which aredescribed in more detail below. In this embodiment, the flexible overlayis sized to be placed over and enclose the area of the wound to betreated and adapted to maintain reduced pressure in the area of thewound to be treated. In addition, in this embodiment, the collectionchamber receives and holds fluid aspirated from the wound and thecollection chamber attachment means, which is described in more detailbelow, operably attaches the collection chamber to the impermeableflexible overlay in a manner so that reduced pressure and the fluid arepermitted to flow between the collection chamber and the impermeableflexible overlay. Second, the collection chamber is operably connectedwith a vacuum system for producing reduced pressure in the volume withinthe collection chamber and in the volume under the flexible overlay inthe area of the wound to be treated. Third, the flexible overlay iscollapsed in the approximate direction of the wound when reducedpressure is supplied to the volume under the flexible overlay in thearea of the wound so that an approximately hermetic seal (described inmore detail herein) is formed between the impermeable flexible overlayand the body in the area of the wound. Fourth, reduced pressure ismaintained until the area of the wound being treated has progressedtoward a selected stage of healing. In other embodiments of this thirdaspect of the first version of the invention, the method furthercomprises the step of placing tissue protection means on the tissue ofthe body that is to be approximately adjacent to the impermeableflexible overlay, such step being performed prior to positioning theimpermeable flexible overlay over the area of the wound to be treated.The tissue protection means, which is described in more detail below,protects and strengthens the tissue of the body adjacent to the flexibleoverlay at the wound site. In yet other embodiments of this third aspectof the first version of the invention, the method further comprises thestep of placing wound packing means (described in more detail herein)between the wound and the impermeable flexible overlay in the area ofthe wound to be treated, such step being performed prior to positioningthe impermeable flexible overlay over the area of the wound to betreated. In still other embodiments of this third aspect of the firstversion of the invention, the reduced pressure under the impermeableoverlay in the area of the wound is in the range from approximately 20mm of Hg below atmospheric pressure to approximately 125 mm of Hg belowatmospheric pressure. In still other embodiments of this third aspect ofthe first version of the invention, the reduced pressure is applied in acyclic nature, the cyclic nature providing alternating time periods ofapplication of reduced pressure and without application of reducedpressure.

There has thus been outlined, rather broadly, the more primary featuresof the present invention. There are additional features that are alsoincluded in the various embodiments of the invention that are describedhereinafter and that form the subject matter of the claims appendedhereto. In this respect, it is to be understood that the invention isnot limited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the following drawings. This invention may be embodied inthe form illustrated in the accompanying drawings, but the drawings areillustrative only and changes may be made in the specific constructionillustrated and described within the scope of the appended claims. Theinvention is capable of other embodiments and of being practiced andcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein are for the purpose of thedescription and should not be regarded as limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe preferred embodiments of the present invention, will be betterunderstood when read in conjunction with the appended drawings, inwhich:

FIG. 1A is a perspective view of an embodiment of an impermeableflexible overlay of a wound treatment appliance of a first version ofthe present invention, as viewed from the side of and above the flexibleoverlay comprising the wound treatment appliance (as the flexibleoverlay would be oriented when placed on the body of a patient);

FIG. 1B is a perspective view of another embodiment of an impermeableflexible overlay of a wound treatment appliance of the first version ofthe present invention, as viewed from the side of and above the flexibleoverlay comprising the wound treatment appliance (as the flexibleoverlay would be oriented when placed on the body of a patient);

FIG. 1C is a perspective view of another embodiment of an impermeableflexible overlay of a wound treatment appliance of the first version ofthe present invention, as viewed from the side of and above the flexibleoverlay comprising the wound treatment appliance (as the flexibleoverlay would be oriented when placed on the body of a patient);

FIG. 1D is a perspective view of another embodiment of an impermeableflexible overlay of a wound treatment appliance of the first version ofthe present invention, as viewed from the side of and above the flexibleoverlay comprising the wound treatment appliance (as the flexibleoverlay would be oriented when placed on the body of a patient);

FIG. 1E is a perspective view of another embodiment of an impermeableflexible overlay of a wound treatment appliance of the first version ofthe present invention as viewed from the side of and below the flexibleoverlay comprising the wound treatment appliance (as the flexibleoverlay would be oriented when placed on the body of a patient);

FIG. 2A is a view of an embodiment of a wound treatment appliance of thefirst version of the present invention, in which an embodiment of animpermeable flexible overlay, shown in perspective view from the side ofand above the flexible overlay, covers a wound, and in which anembodiment of a vacuum system, depicted generally and shown in schematicelevation view, provides reduced pressure within the area under theflexible overlay;

FIG. 2B is a sectional elevational detailed view of an embodiment of acollection container and the shutoff mechanism portion of the collectionsystem of FIG. 2A;

FIG. 3 is a view of an embodiment of a wound treatment appliance of thefirst version of the present invention, in which an embodiment of animpermeable flexible overlay, shown in cross-sectional elevational viewfrom the side of the flexible overlay, covers a wound and wound packingmeans, and in which an embodiment of a vacuum system, shown inelevational view, provides reduced pressure within the area under theflexible overlay;

FIG. 4 is a view of an embodiment of a wound treatment appliance of thefirst version of the present invention, in which an embodiment of animpermeable flexible overlay, shown in cross-sectional elevational viewfrom the side of the flexible overlay, covers a wound, and in which anembodiment of a vacuum system, shown in perspective view from the sideof and below the vacuum system, provides reduced pressure within thearea under the flexible overlay;

FIG. 5 is a view of an embodiment of a wound treatment appliance of asecond version of the present invention, in which an embodiment of animpermeable flexible overlay, shown in perspective view from the side ofand above the flexible overlay, covers a wound, and in which anembodiment of a vacuum system, depicted generally and shown in schematicelevation view, provides reduced pressure within the area under theflexible overlay; and

FIG. 6 is a view of another embodiment of a wound treatment appliance ofa second version of the present invention, in which an embodiment of animpermeable flexible overlay is shown in partially broken awayperspective view from the side of and above the flexible overlay (as theflexible overlay would be oriented when placed on the body of apatient), and in which an embodiment of a vacuum system, depictedgenerally and shown in schematic elevation view, provides reducedpressure within the area under the flexible overlay.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention, a wound treatment appliance isprovided for treating all or a portion of a wound by applying reducedpressure (i.e., pressure that is below ambient atmospheric pressure) tothe portion of the wound to be treated in a controlled manner for aselected time period in a manner that overcomes the disadvantages ofcurrently existing apparatus. One embodiment of a first aspect of afirst version of the invention is a wound treatment appliance 10 that iscomprised of the fluid impermeable flexible overlay 20 illustrated inFIG. 1A and reduced pressure supply means, which are described in moredetail below. In this embodiment, the flexible overlay 20 has anapproximately elongated conical shape, having an opening 21 with anopening perimeter 22 adjacent to the opening 21 (at the base of theelongated conical shape) that is approximately elliptical in shape. Theflexible overlay 20 illustrated in FIG. 1A is in its natural shape, asit exists prior to being applied to a patient for treatment of all or aportion of a wound. In other embodiments, the flexible overlay 20 mayhave other shapes. For example, the flexible overlay 20 may beapproximately conical in shape, rather than the approximately elongatedconical shape illustrated in FIG. 1A. As another example, as illustratedin FIG. 1B, only the bottom portion 23 a of the flexible overlay 20 amay have an approximately elongated conical shape. In this embodiment,and in the same manner as illustrated in FIG. 1A, the bottom portion 23a has an opening 21 a with an opening perimeter 22 a adjacent to theopening 21 a (at the base of the elongated conical shape) that isapproximately elliptical in shape. In the embodiment of the flexibleoverlay illustrated in FIG. 1B, the top portion 24 a is flatter than thecomparable portion of the flexible overlay 20 in the embodimentillustrated in FIG. 1A. In other embodiments, the top portion 24 a ofthe flexible overlay 20 a may have almost any shape that is adaptable toa bottom portion 23 a having an approximately elongated conical shape.In addition, in yet other embodiments of this first aspect of the firstversion of the invention, the bottom portion 23 a of the flexibleoverlay 20 a may be in the approximate shape of a cone, rather than theelongated conical shape illustrated in FIG. 1B. In yet anotherembodiment, as illustrated in FIG. 1C, the flexible overlay 20 b iscomprised of six cover portions 23 b, 23 b′, where the cover portions 23b are viewable in FIG. 1C and the cover portions 23 b′ are illustratedby phantom lines. In this embodiment, each of such cover portions 23 b,23 b′ is approximately triangular in shape, and one point of each of theat least three cover portions 23 b, 23 b′ is joined to form an apex 24 bof the impermeable flexible overlay 20 b. One side of each cover portion23 b, 23 b′ adjacent to the apex 24 b is joined to an adjacent side ofanother of such cover portions 23 b, 23 b′ so that the bases 22 b, 22 b′of the cover portions 23 b, 23 b′, respectively, form an opening 21 bsized to be placed over and enclose the area of the wound to be treated.In other embodiments, the flexible overlay 20 b may have a differentnumber of cover portions 23 b, 23 b′. Preferably, in these embodiments,there are at least three cover portions 23 b, 23 b′. In addition, in yetother embodiments, the flexible overlay 20 b may have cover portions 23b, 23 b′ having a different shape, such as trapezoidal or parabolic.Another embodiment of the first aspect of the first version of thepresent invention is illustrated in FIG. 1D. In this embodiment, theoverlay 20 c is approximately cup-shaped with an approximately circularopening 21 c, which has an opening perimeter 22 c adjacent to theopening 21 c. The overlay 20 c of this embodiment also has a pluralityof channels 29 c disposed in the surface thereof as suction assistmeans, which are described in more detail below. In still otherembodiments, the flexible overlay 20, 20 a, 20 b, 20 c may be of almostany shape that may be adaptable for treating all or a portion of awound, as long as the flexible overlay 20, 20 a, 20 b, 20 c is flexible,as described in more detail below, and the interior surface of theflexible overlay 20, 20 a, 20 b, 20 c is adapted to make anapproximately hermetic seal with the body of the patient at the site ofthe wound, as described in more detail below. For example, and asclarification, the flexible overlay 20, 20 a, 20 b, 20 c or portionsthereof may have an approximately tetrahedral, hexahedral, polyhedral,spherical, spheroidal, arcuate, or other shape or combination of allsuch shapes. Referring again to FIG. 1A as an example, in someembodiments of this first aspect of the first version of the invention,the interior surface of the flexible overlay 20 is adapted to make anapproximately hermetic seal with the body of the patient at the site ofthe wound by having a surface area larger than the surface area of theportion of the body of the patient covered by the flexible overlay 20,as described in more detail below.

The preferred shape and size of the flexible overlay 20, 20 a, 20 b, 20c is dependent upon the size of the portion of the wound to be treated,the shape and contour of the portion of the body that is to be coveredby the flexible overlay 20, 20 a, 20 b, 20 c at the site of the wound,the magnitude of the reduced pressure to be maintained under theflexible overlay 20, 20 a, 20 b, 20 c. More preferred, as illustrated inFIG. 1B, the flexible overlay 20 a has an approximately elongatedconically shaped bottom portion 23 a. Most preferred, as illustrated inFIG. 1A, the flexible overlay 20 is shaped approximately as an elongatedcone. The preferred thickness of the portion 25, 25 a, 25 b, 20 c of theflexible overlay 20, 20 a, 20 b, 20 c adjacent to the open end 21, 21 a,21 b, 20 c of the flexible overlay 20, 20 a, 20 b, 20 c is dependentupon the size and shape of the flexible overlay 20, 20 a, 20 b, 20 c,the shape and contour of the portion of the body that is to be coveredby the flexible overlay 20, 20 a, 20 b, 20 c at the site of the wound,the magnitude of the reduced pressure to be maintained under theflexible overlay 20, 20 a, 20 b, 20 c, and other factors, such as thedepth of the wound and the amount of the desired collapse of theflexible overlay 20, 20 a, 20 b, 20 c. For example, in the embodimentillustrated in FIG. 1A, for a flexible overlay 20 constructed ofsilicone and having an approximately elongated conical shape with anopening 21 having a major diameter of approximately 7 inches and a minordiameter of approximately 4 inches, the preferred thickness of theportion 25 of the flexible overlay 20 adjacent to the open end 21 of theflexible overlay 20 is in the range from 1/32 inches to 3/32 inches.More preferred in this embodiment, the thickness of the portion 25 ofthe flexible overlay 20 adjacent to the open end 21 of the flexibleoverlay 20 is approximately 1/16 inches. It is to be noted that in otherembodiments the thickness of the flexible overlay 20, including theportion 25 of the flexible overlay 20 adjacent to the open end 21 of theflexible overlay 20, may vary from location to location on the flexibleoverlay 20.

In the embodiment of the flexible overlay 20 illustrated in FIG. 1A, theflexible overlay 20 has a series of raised beads 26 on the outsidesurface of the flexible overlay 20. In this embodiment, the raised beads26 are generally parallel to the perimeter 22 of the opening 21 of theflexible overlay 20. The same is also true of the raised bead 26 b ofthe flexible overlay 20 b of the embodiment illustrated in FIG. 1C. Inother embodiments, such as that illustrated in FIG. 1B, the raised beads26 a may have a different orientation. In still other embodiments, theraised beads 26, 26 a, 26 b may be in almost any orientation desired bythe user of the wound treatment appliance 10, 10 a, 10 b. In variousembodiments of this first aspect of the first version of the invention,as illustrated in FIG. 1A, the raised beads 26 may provide a guide forthe user administering the reduced pressure treatment to cut away aportion of the flexible overlay 20, so that the perimeter 22 of theopening 21 of the flexible overlay 20 is smaller than it was originally.For example, by cutting along the parallel raised beads 26 of theflexible overlay 20 of FIG. 1A, the size of the opening 21 of theflexible overlay 20 can be made smaller while the shape of the perimeter22 remains approximately the same. It is to noted, however, that invarious embodiments of this first aspect of the first version of theinvention, as described in more detail below, the flexible overlay 20may be cut into different shapes in order to adapt the flexible overlay20 for use with different shapes and contours of the surface of the bodyat the site of the wound.

In other embodiments of this first aspect of the present invention, asillustrated in FIG. 1D, the flexible overlay 20 c may be furthercomprised of suction assist means to assist in the application ofreduced pressure to the portion of the wound to be treated, as well asremoval of exudate from the wound. For example, in the illustratedembodiment, the overlay 20 c has a plurality of channels 29 c disposedin the surface thereof. The channels 29 c may generally provide aconduit for reduced pressure to reach the various portions of the woundto be treated. In addition, exudate aspirated from the various portionsof the wound to be treated may flow along the channels 29 c to thereduced pressure supply means (not illustrated), where the exudate maybe removed from the flexible overlay 20 c by means of the reducedpressure supply means cooperating with the reduced pressure supplysource, as described in more detail below. In some of these embodiments,the channels 29 c may be operably connected to the reduced pressuresupply means through a port 27 c, as described in more detail below. Inthe illustrated embodiment, there are three continuous channels 29 crecessed into the surface of the overlay 20 c, which are joined togethernear the apex of the flexible overlay 20 c at the port 27 c. In otherembodiments, there may be more or fewer channels 29 c. For example, inother embodiments there may be fewer channels 29 c and the channels 29 cmay be of the same size or of a different size. In yet otherembodiments, there may be many channels 29 c, in which case the channels29 c may generally be of a smaller size. In addition, the channels 29 cmay be disposed in other positions relative to the flexible overlay 20c. For example, the channels 29 c may be located at different locationson the flexible overlay 20 c and may have a different orientation, suchas being curved in a “corkscrew” pattern or crossed in a “checkerboard”pattern, rather than being oriented as illustrated in FIG. 1D.

In still other embodiments, the channels 29 c as suction assist means,may have a different structure and form. For example, the channels 29 cmay be in the form of tubes positioned within the volume of the flexibleoverlay 20 c, as illustrated in FIG. 1E, wherein the tubes have one ormore perforations so that the channels 29 c are in fluid communicationwith the volume under the flexible overlay 20 c in the area of the woundto be treated. As another example, the channels 29 c may have stiffeningmembers, such as raised beads (“ribs”) of material, so that the channels29 c have a greater stiffness than the remaining portions of theflexible overlay 20 c. In other embodiments, the channels 29 c, assuction assist means, may be in the form of portions that are raisedabove the surface of the flexible overlay 20 c. Such raised portions mayappear as “dimples” when viewed from above the flexible overlay 20 c.

The channels 29 c, as suction assist means, may also be of almost anysize, shape and pattern to accomplish their intended purpose. Thepreferred size, shape and pattern are dependent upon the size and shapeof the flexible overlay 20 c, the type of wound to be treated, the levelof reduced pressure to be used in the treatment, the amount of exudateanticipated, the type of reduced pressure supply means utilized, and theindividual preference of the user of the appliance 10 c. Where utilized,channels 29 c may be molded or cut into the surface of the flexibleoverlay 20 c or, if in the shape of tubes, may be molded as a part ofthe surface of the flexible overlay 20 c or may be welded or fused tothe surface of the flexible overlay 20 c. It is to be noted that thevarious embodiments of the flexible overlays 20, 20 a, 20 b illustratedand described above in connection with FIG. 1A, FIG. 1B, and FIG. 1C,respectively, may each also comprise suction assist means, and thereforemay also comprise any of the various embodiments of the channels 29 cillustrated and described above in connection with FIG. 1D or FIG. 1E.

In the various embodiments of this first aspect of the first version ofthe invention, the flexible overlay 20, 20 a, 20 b, 20 c may becomprised of almost any medical grade flexible material that iscurrently known in the art or that may be developed in the art in thefuture, as long as such material is fluid-impermeable, suitable forpurposes of wound treatment (e.g., can be sterilized and does not absorbsignificant amounts of wound exudate), and is capable of forming anapproximately hermetic seal with the surface of the body at the site ofthe wound, as described in more detail below. For example, the flexibleoverlay 20, 20 a, 20 b, 20 c may be comprised of rubber (includingneoprene), and flexible polymer materials, such as silicone, siliconeblends, silicone substitutes, polyester, vinyl, polyimide, polyethylenenapthalate, polycarbonates, polyester-polycarbonate blends, or a similarpolymer, or combinations of all such materials. Preferably, the flexibleoverlay 20, 20 a, 20 b, 20 c is comprised of silicone. Although theraised beads 26, 26 a, 26 b may be constructed of a material differentfrom the material comprising the remainder of the flexible overlay 20,20 a, 20 b in various embodiments of the invention, the raised beads 26,26 a, 26 b are preferably constructed from the same material comprisingthe remainder of the flexible overlay 20, 20 a, 20 b. In otherembodiments, the raised beads 26, 26 a, 26 b may be placed on theflexible overlay 20, 20 a, 20 b by means of a mark, such as indelibleink, on the surface of the flexible overlay 20, 20 a, 20 b. In someembodiments, the channels 29 c (and all other suction assist means) maybe constructed of a material different from the material comprising theremainder of the flexible overlay 20 c. For example, one or more of thechannels 29 c may be constructed of a slightly more rigid material thanthe remainder of the flexible overlay 20 c so that such channel 29 c orchannels 29 c better retain their shape. In other embodiments, thechannels 29 c may be constructed of the same material comprising theremainder of the flexible overlay 20 c, but the channels 29 c may have adifferent thickness than the remainder of the flexible overlay 29 c. Forexample, one or more of the channels 29 c may be slightly thicker thanthe remainder of the flexible overlay 20 c so that such channel 29 c orchannels 29 c better retain their shape. In still other embodiments, thechannels 29 c may be constructed of the same material comprising, andhave the same thickness as, the remainder of the flexible overlay 20 c.Preferably, the channels 29 c are constructed of the same material as,but have a slightly greater thickness than, the remaining portions ofthe flexible overlay 20 c. It is to be noted that in various embodimentsof this first aspect of the first version of the invention, the flexibleoverlay 20, 20 a, 20 b, 20 c may be constructed in whole or in part ofgas-permeable materials, allowing limited amounts of oxygen to penetratethe flexible overlay 20, 20 a, 20 b, 20 c so that the area of the woundunder the flexible overlay 20, 20 a, 20 b, 20 c can “breathe.” It isalso to be noted that all portions of the flexible overlay 20, 20 a, 20b, 20 c are preferably constructed of one type of polymer material, suchas silicone. The flexible overlay 20, 20 a, 20 b, 20 c may beconstructed using any suitable means currently known in the art or thatmay be developed in the art in the future. For example, a flexibleoverlay 20, 20 a, 20 b, 20 c constructed of silicone may be manufacturedby means of injection molding. As another example, where the channels 29c are constructed of a different material from the remainder of theflexible overlay 20 c, the channels 29 c may be welded or fused to theremaining portions of the flexible overlay 20 c.

In the embodiments of the flexible overlay 20, 20 a, 20 b, 20 cillustrated in FIG. 1A, FIG. 1B, FIG. 1C, and FIG. 1D, respectively,each of the flexible overlays 20, 20 a, 20 b, 20 c further comprises aport 27, 27 a, 27 b, 27 c adapted to receive a reduced pressure supplymeans to supply reduced pressure to the area of the wound under theflexible overlay 20, 20 a, 20 b, 20 c. Although the port 27 ispositioned at approximately the apex of the elongated cone-shapedflexible overlay 20 in the embodiment illustrated in FIG. 1A, and theport 27 b is positioned at approximately the apex 24 b of thetriangular-shaped cover portions 23 b, 23 b′ in the embodimentillustrated in FIG. 1C, which is the preferred location, the port may belocated at another location on the flexible overlay in otherembodiments. In such embodiments, and referring to FIG. 1B as anexample, the port 27 a (and alternate port 27 a′) may be located atalmost any location on the surface of the flexible overlay 20 a as longas the port 27 a, 27 a′ does not adversely affect the ability of theflexible overlay 20 a to make an approximately hermetic seal with thesurface of the body at the wound site, as described in more detailbelow. For example, the port 27 a, 27 a′ may not be located too close tothe perimeter 22 a of the opening 21 a of the flexible overlay 20 abecause the approximately hermetic seal with the surface of the body istypically formed at that location. In the embodiment of the flexibleoverlay 20 a illustrated in FIG. 1B, the alternate port 27 a′ maypreferably be located at any location on the top portion 24 a of theflexible overlay 20 a, and more preferably, the port 27 a is located atthe center of the top portion 24 a of the flexible overlay 20 a.Referring again to FIG. 1A as an example, although the port 27 may beconstructed of a material different from the material comprising theremainder of the flexible overlay 20 in various embodiments of theinvention, the port 27 is preferably constructed from the same materialcomprising the remainder of the flexible overlay 20. In the embodimentsof the flexible overlay 20, 20 a, 20 b illustrated in FIG. 1A, FIG. 1B,and FIG. 1C, respectively, the ports 27, 27 a, 27 b are generallycylindrical in shape and are further comprised of an approximatelycylindrical duct 28, 28 a, 28 b, respectively, that extends from the topof each of the ports 27, 27 a, 27 b, respectively, to the bottom of theports 27, 27 a, 27 b, respectively. The ports 27, 27 a, 27 b of theseembodiments are thus able to receive a vacuum system or reduced pressuresupply means, which are described in more detail below, adapted to beconnected to this shape of port 27, 27 a, 27 b, respectively, andchannel 28, 28 a, 28 b, respectively. In other embodiments of this firstaspect of the first aspect of the first version of the invention, theports 27, 27 a, 27 b, 27 c or the port ducts 28, 28 a, 28 b,respectively, or both may have different shapes and configurations asmay be desired to adapt and connect the ports 27, 27 a, 27 b,respectively, and the port ducts 28, 28 a, 28 b, respectively, to thevacuum system or reduced pressure supply means, which are described inmore detail below. For example, the port 27 c of the flexible overlay 20c illustrated in FIG. 1D is formed as a single piece with the remainderof the flexible overlay 20 c. In this example, the port 27 c has acylindrical duct 28 c that extends through the port 27 c and generallyfollows the contours of the channels 29 c at its lower end.

An embodiment of a second aspect of the first version of the presentinvention is the wound treatment appliance 110 illustrated in FIG. 2A.In this embodiment, the wound treatment appliance 110 is comprised of awound treatment device 115 and a vacuum system, generally designated150, that is operably connected to, and provides a supply of reducedpressure to, the wound treatment device 115. Also in this embodiment,the wound treatment device 115 is comprised of a flexible overlay 120.In addition, in this embodiment, the vacuum system 150 is furthercomprised of a reduced pressure supply source, generally designated 130,which is illustrated schematically and described in more detail below,and reduced pressure supply means, generally designated 140, which areillustrated schematically and described in more detail below. Also inthis embodiment, the reduced pressure supply means 140 are used toconnect the reduced pressure supply source 130 to the flexible overlay120 in a manner so that reduced pressure is supplied to the volume underthe flexible overlay 120 in the area of the wound 160, as described inmore detail below. In the embodiment of the second aspect of the firstversion of the invention illustrated in FIG. 2A, the flexible overlay120 has substantially the same structure, features, characteristics andoperation as the flexible overlay 20 described above and illustrated inconnection with FIG. 1A. It is to be noted, however, that in otherembodiments of this second aspect of the first version of the invention,the flexible overlay 120 may have substantially the same structure,features and characteristics as any embodiment of all of the flexibleoverlays 20, 20 a, 20 b, 20 c of the first aspect of the first versionof the invention described above and illustrated in connection with FIG.1A, FIG. 1B, FIG. 1C, and FIG. 1D. FIG. 2A also illustrates an exampleof how the embodiment of the flexible overlay 20 illustrated in FIG. 1Amay be used to provide reduced pressure treatment for a wound 160 on thebody 170 of a patient. In this example, the flexible overlay 120 isplaced over and encloses the entire wound 160, as described in moredetail below. In other embodiments, the flexible overlay 120 need notenclose the entire wound 160.

In the embodiment illustrated in FIG. 2A, the reduced pressure supplysource 130 of the vacuum system 150, which produces a source of reducedpressure or suction that is supplied to the flexible overlay 120, iscomprised of a vacuum pump 131, a control device 132, and a filter 133.Although the preferred means of producing the reduced pressure orsuction is a vacuum pump 131 in this embodiment, in other embodiments ofthis second aspect of the first version of the invention other means maybe used, such as an outlet port of a centralized hospital vacuum system.In the illustrated embodiment, predetermined amounts of suction orreduced pressure are produced by the vacuum pump 131. The vacuum pump131 is preferably controlled by a control device 132, such as a switchor a timer that may be set to provide cyclic on/off operation of thevacuum pump 131 according to user-selected intervals. Alternatively, thevacuum pump 131 may be operated continuously without the use of acyclical timer. In addition, in some embodiments the control device 132may provide for separate control of the level of reduced pressureapplied to the wound 160 and the flow rate of fluid aspirated from thewound 160. In these embodiments, relatively low levels of reducedpressure may be maintained in the area of the wound 160 under the woundtreatment device 115, while still providing for the removal of arelatively large volume of exudate from the wound 160. A filter 133,such as a micropore filter, is preferably attached to the inlet of thevacuum pump 131 to prevent potentially pathogenic microbes or aerosolsfrom contaminating, and then being vented to atmosphere by, the vacuumpump 131. In other embodiments, the filter 133 may also be a hydrophobicfilter that prevents any exudate from the wound from contaminating, andthen being vented to atmosphere by, the vacuum pump 131. It is to benoted that in other embodiments of the invention, the reduced pressuresupply source 130 may not have a filter 133 or a control 132 or anycombination of the same.

In the embodiment of the second aspect of the first version of theinvention illustrated in FIG. 2A, the reduced pressure supply means 140of the vacuum system 150, which are used to connect the reduced pressuresupply source 130 to the flexible overlay 120 so that reduced pressureis supplied to the volume under the flexible overlay 120 in the area ofthe wound 160 is comprised of at least one tubing member 141. In thisembodiment, the at least one tubing member 141 is sufficiently flexibleto permit movement of the at least one tubing member 141, but issufficiently rigid to resist constriction when reduced pressure issupplied to the flexible overlay 120 or when the location of the wound160 is such that the patient must sit or lie upon the at least onetubing member 141 or upon the wound treatment device 115. In theembodiment illustrated in FIG. 2A, the at least one tubing member 141 isconnected to the flexible overlay 120 by inserting one end of the atleast one tubing member 141 into the opening 128 of the port 127 of theflexible overlay 120. In this embodiment, the at least one tubing memberis held in place in the opening 128 by means of an adhesive. It is to benoted that in other embodiments of this second aspect of the firstversion of the invention, the at least one tubing member 141 may beconnected to the port 127 of the flexible overlay 120 using any suitablemeans currently known in the art or developed in the art in the future.Examples include variable descending diameter adapters (commonlyreferred to as “Christmas tree” adapters), luer lock fittings andadapters, clamps, and combinations of such means. Alternatively, theport 127 and the at least one tubing member 141 may be fabricated as asingle piece, as is the case with the port 27 c of the flexible overlay20 c, as illustrated and described above in connection with FIG. 1D.Similar means may be used to connect the other end of the at least onetubing member 141 to the vacuum pump 131 or other reduced pressuresupply source 130 providing the reduced pressure.

In the embodiment illustrated in FIG. 2A, the reduced pressure supplymeans 140 further comprises a fluid collection system, generallydesignated 142, that is interconnected between the suction pump 131 andthe flexible overlay 120 to remove and collect any exudate that may beaspirated from the wound 160 and collected by the flexible overlay 120.The flexible overlay 120 functions to actively draw fluid or exudatefrom the wound 160. Collection of exudate in a fluid collection system142 intermediate the pump 131 and the flexible overlay 120 is desirableto prevent clogging of the pump 131. The fluid collection system 142 iscomprised of a fluid-impermeable collection container 143 and a shutoffmechanism 144, which are described in more detail below in connectionwith FIG. 2B. The container 143 may be of any size and shape capable ofintercepting and retaining a predetermined amount of exudate. Manyexamples of such containers are available in the relevant art. Referringto FIG. 2B, which is an enlarged elevational cross-sectional view of thepreferred embodiment of the container 143, the container 143 includes afirst port 143 a at the top opening of the container 143 for sealedconnection to tubing member 141 a, where the other end of the tubingmember 141 a is connected to the flexible overlay 120. The first port143 a enables suction to be applied to the flexible overlay 120 throughthe tubing 141 a and also enables exudate from the portion of the wound160 covered by the flexible overlay 120 to be drained into the container143. The container 143 provides a means for containing and temporarilystoring the collected exudate. A second port 143 b is also provided onthe top of the container 143 to enable the application of suction fromthe vacuum pump 131. The second port 143 b of the collection system 142is connected to the vacuum pump 131 by tubing member 141 b. Thecollection system 142 is sealed generally gas-tight to enable thesuction pump 131 to supply suction to the flexible overlay 120 throughthe collection system 142.

The embodiment of the collection system 142 illustrated in FIG. 2B alsoincludes a shutoff mechanism for halting or inhibiting the supply of thereduced pressure to the flexible overlay 120 in the event that theexudate aspirated from the wound 160 exceeds a predetermined quantity.Interrupting the application of suction to the flexible overlay 120 isdesirable to prevent exsanguination in the unlikely event a blood vesselruptures under the flexible overlay 120 during treatment. If, forexample, a blood vessel ruptures in the vicinity of the wound 160, ashut-off mechanism would be useful to prevent the vacuum system 150 fromaspirating any significant quantity of blood from the patient. In thepreferred embodiment of the shutoff mechanism 144, as illustrated inFIG. 2B, the shutoff mechanism 144 is a float valve assembly in the formof a ball 144 a which is held and suspended within a cage 144 bpositioned below a valve seat 144 c disposed within the opening at thetop of the container below the second port 143 b that will float uponthe exudate and will be lifted against the valve seat 144 c as thecontainer 143 fills with exudate. When the ball 144 a is firmly seatedagainst the valve seat 144 c, the float valve blocks the second port 143b and thereby shuts off the source of suction from the vacuum system150. In other embodiments of the container 143, other types ofmechanisms may also be employed to detect the liquid level within thecontainer 143 in order to arrest operation of the vacuum system 50. Inaddition, in various embodiments of this second version of theinvention, the shutoff mechanism 144 may be comprised of any means thatenables the vacuum system 150 to halt the supply of reduced pressure tothe flexible overlay 120 at any time that the volume of exudate from thewound 160 exceeds a predetermined amount. Such means may includemechanical switches, electrical switches operably connected to thevacuum system controller 132, optical, thermal or weight sensorsoperably connected to the vacuum system controller 132, and any othermeans that are currently known in the relevant art or that may bedeveloped in the art in the future.

In some embodiments of this second version of the invention, the woundtreatment appliance 110 further comprises tissue protection means 175 toprotect and strengthen the body tissue 171 that is adjacent to theflexible overlay 120 at the wound site 161. The tissue protection means175 protects the tissue 171 by preventing abrasion and maceration of thetissue. Preferably, the tissue protection means 175 is a hydrocolloidmaterial, such as COLOPAST Hydrocolloid 2655, anhydrous lanoline, or anycombination of such hydrocolloid materials. More preferably, the tissueprotection means 175 is COLOPAST Hydrocolloid 2655. The tissueprotection means 175 may be applied to the body tissue 171 to beprotected, or it may be applied to the surface of the flexible overlay120 that is to be in contact with the body tissue 171, or both, prior toplacing the flexible overlay 120 on the surface of the body 170 at thewound site 161. It is to be noted that application of the tissueprotection means 175 to the body tissue 171 that is adjacent to theflexible overlay 120 at the wound site 161 may only entail applicationof the tissue protection means 175 to the portion of the body tissue 171adjacent to the flexible overlay 120 that requires such protection.

FIG. 2A also illustrates an example of how the embodiment of theflexible overlay 20 illustrated in FIG. 1A (which is flexible overlay120 in FIG. 2A) may be used to provide reduced pressure treatment for awound 160 on the body 170 of a patient. In this example, the flexibleoverlay 120 is removed from an aseptic package in which it is stored.The flexible overlay 120 is then placed over and encloses the portion ofthe wound 160 to be treated, which is the entire wound 160 in thisexample. The flexible overlay 120 is also connected to the vacuum system150 by means of the port 127 on the flexible overlay 120 either before,after or during the placement of the flexible overlay 120 over the wound160. Where it is deemed necessary by the user of the wound treatmentappliance 110, tissue protection means 175, as described above, may beplaced on a portion of the flexible overlay 120, on the body tissue 171to be protected, or both, prior to placing the flexible overlay 120 overthe wound 160. In the example illustrated in FIG. 2A, the interiorsurface portions 129 of the flexible overlay 120 positioned around andadjacent to the perimeter 122 of the opening 121 of the flexible overlay120 are at (or can be deformed to be at) a relatively acute anglerelative to the surrounding surface of the body 170. Such deformationmay be caused by the user of the wound treatment appliance 110 exertingmild pressure on the portions 129 of the flexible overlay 120 positionedaround and adjacent to the perimeter 122 of the opening 121 of theflexible overlay 120 so that they are in contact with the surface of thebody 170 surrounding the wound 160. Reduced pressure is then supplied tothe flexible overlay 120 by the vacuum system 150. When reduced pressureis applied to the volume under the flexible overlay 120 in the area ofthe wound 160, the flexible overlay 120 is drawn downward by the reducedpressure, collapsing the flexible overlay 120 in the approximatedirection of the wound 160. As the flexible overlay 120 collapses, theportions 129 of the flexible overlay 120 adjacent to the perimeter 122of the opening 121 of the flexible overlay 120 are drawn tightly againstthe surface of the body 170 surrounding the wound 160, thus forming anapproximately hermetic seal between the portions 129 of the flexibleoverlay 120 adjacent to the perimeter 122 of the opening 121 of theflexible overlay 120 and the portion of the body 170 adjacent to suchportions 129. References to an “approximately hermetic seal” hereinrefer generally to a seal that may be made gas-tight and liquid-tightfor purposes of the reduced pressure treatment of the wound 160. It isto be noted that this seal need not be entirely gas-tight andliquid-tight. For example, the approximately hermetic seal may allow fora relatively small degree of leakage, so that outside air may enter thevolume under the flexible overlay 120 in the area of the wound 160, aslong as the degree of leakage is small enough so that the vacuum system150 can maintain the desired degree of reduced pressure in the volumeunder the flexible overlay 120 in the area of the wound 160. As anotherexample, the approximately hermetic seal formed by the collapsingflexible overlay 120 may not be solely capable of maintaining thereduced pressure in the volume under the flexible overlay 120 in thearea of the wound 160. This may be the case if the shape of the body 170at the site of the wound 160 does not allow for such a seal. In otherinstances, as may be the case with the flexible overlay 20 c illustratedand described above in connection with FIG. 1D, the perimeter 22 cadjacent to the opening 21 c may not have a relatively acute anglerelative to the surrounding tissue, so that additional means is requiredto make an approximately hermetic seal. In these cases, it may benecessary to provide supplemental sealing means, which are used toprovide a seal between the portions of the flexible overlay 120 and thebody 170 where the approximately hermetic seal is not adequate to permitreduced pressure to be maintained in the volume under the flexibleoverlay 120 in the area of the wound 160. For example, in theillustrated embodiment, the supplemental sealing means 176 may be anadhesive applied to a portion of the impermeable overlay 120 or aportion of the body 170 in a manner similar to the application of thetissue protection means 175 described above. In other embodiments, thesupplemental sealing means 176 may be comprised of almost any suitablemeans to provide an adequate seal. For example, the supplemental sealingmeans 176 may be comprised of an adhesive, an adhesive tape, a stretchfabric that covers the wound treatment device 115 and is wrapped arounda portion of the body 170 of the patient in the area of the wound 160,lanoline, or any combination of such means. It is also to be noted thatin this embodiment at least one fold 129 a forms in the surface of theflexible overlay 120 when it collapses, so that exudate aspirated by thewound 160 flows along the at least one fold 129 a to the port 127, wherethe exudate is removed from the flexible overlay 120 by means of thereduced pressure supply means 140 cooperating with the reduced pressuresupply source 130. Thus, in the preferred embodiments, the impermeableoverlay 120 is constructed of a material, and has a size, shape andthickness, that permits the flexible overlay 120 to collapse in thedirection of the wound 160 and form an approximately hermetic seal withthe body 170 when reduced pressure is applied to the volume under theflexible overlay 120 in the area of the wound 160, while still beingrigid enough to support the approximately hermetic seal with the body170 and to support the at least one fold 129 a. In embodiments of theoverlay 120 comprising suction assist means, such as the channels 29 cof the flexible overlay 20 c illustrated and described above inconnection with FIG. 1D, exudate from the wound 160 may also flow alongsuch channels to the port 127. It is also to be noted that the volumeunder the flexible overlay 120 in the area of the wound 160 may beminimal while the flexible overlay 120 is in its collapsed state overthe wound 160. In the preferred embodiments of this second aspect of thefirst version of the invention, the reduced pressure maintained in thevolume under the flexible overlay 120 in the area of the wound 160 is inthe range from approximately 20 mm of Hg below atmospheric pressure toapproximately 125 mm of Hg below atmospheric pressure. In yet otherembodiments, the reduced pressure is applied to the flexible overlay 120in a cyclic nature, the cyclic nature providing alternating time periodsof application of reduced pressure and non-application of reducedpressure. In all of these embodiments, the reduced pressure ismaintained in the volume under the flexible overlay 120 in the area ofthe wound 160 until the wound 160 has progressed toward a selected stageof healing.

An embodiment of a third aspect of the first version of the invention isthe wound treatment appliance 210 illustrated in FIG. 3. In thisembodiment, the wound treatment appliance 210 is comprised of a woundtreatment device 215 and a vacuum system, generally designated 250, thatis operably connected to, and provides a supply of reduced pressure to,the wound treatment device 215. In addition, in this embodiment, thevacuum system 250 is further comprised of a reduced pressure supplysource, generally designated 280, which is described in more detailbelow, and reduced pressure supply means, generally designated 240,which are described in more detail below. Also in this embodiment, thewound treatment device 215 is further comprised of a flexible overlay220, wound packing means 278, and a suction drain 245. In the embodimentof the third aspect of the first version of the invention illustrated inFIG. 3, the flexible overlay 220 has substantially the same structure,features, characteristics and operation as the flexible overlay 20described above and illustrated in connection with FIG. 1A. It is to benoted, however, that in other embodiments of this third aspect of thefirst version of the invention, the flexible overlay 220 may havesubstantially the same structure, features, characteristics andoperation as any embodiment of all of the flexible overlays 20, 20 a, 20b, 20 c of the first aspect of the first version of the inventiondescribed above and illustrated in connection with FIG. 1A, FIG. 1B,FIG. 1C, and FIG. 1D, respectively. In the embodiment illustrated inFIG. 3, the flexible overlay 220 is placed over and encloses the entirewound 260 and is illustrated in a state of partial collapse, with theportion 229 of the flexible overlay 220 adjacent to the opening 221 inthe perimeter 222 of the flexible overlay 220 forming an approximatelyhermetic seal with the adjacent portions 271 of the body 270. It is tobe noted that in various embodiments of this third aspect of the firstversion of the invention, the wound treatment appliance 210 may also becomprised of tissue protection means 275, which may be substantially thesame as the tissue protection means 175 of the second aspect of thefirst version of the invention described above and illustrated inconnection with FIG. 2A.

In the embodiment of the third aspect of the first version of theinvention illustrated in FIG. 3, the wound treatment device 215 isfurther comprised of wound packing means 278, which is placed in thearea of the wound 260 under the flexible overlay 220. In thisembodiment, the flexible overlay 220 is placed over the area of thewound 260 to be treated and the wound packing means 278 when theflexible overlay 220 is positioned on the surface of the body 270 at thesite of the wound 260. In some embodiments of this third aspect of thefirst version of the invention, the wound packing means 278 may beplaced within the wound 260 to prevent overgrowth of the tissue in thearea of the wound 260. For example, and preferably in these cases, thewound packing means 278 may comprised of absorbent dressings, antisepticdressings, nonadherent dressings, water dressings, or combinations ofsuch dressings. More preferably, the wound packing means 278 may becomprised of gauze or cotton or any combination of gauze and cotton. Instill other embodiments of this third aspect of the first version of theinvention, the wound packing means 278 may be comprised of an absorbablematrix adapted to encourage growth of the tissue in the area of thewound 260 into the matrix. In these embodiments, the absorbable matrix(as wound packing means 278) is constructed of an absorbable materialthat is absorbed into the epithelial and subcutaneous tissue in thewound 260 as the wound 260 heals. The matrix (as wound packing means278) may vary in thickness and rigidity, and it may be desirable to usea spongy absorbable material for the patient's comfort if the patientmust lie upon the wound treatment device 215 during treatment. Thematrix (as wound packing means 278) may also be perforated andconstructed in a sponge-type or foam-type structure to enhance gas flowand to reduce the weight of the matrix. Because of the absorbable natureof the absorbable matrix (as wound packing means 278), the matrix shouldrequire less frequent changing than other dressing types during thetreatment process. In other circumstances, the matrix (as wound packingmeans 278) may not need to be changed at all during the treatmentprocess. In some embodiments of this third aspect of the first versionof the invention, the absorbable matrix (as wound packing means 278) maybe comprised of collagens or other absorbable materials or combinationsof all such materials. U.S. patent application Ser. No. 10/652,100,which was filed by the present inventor with the U.S. Patent andTrademark Office on Aug. 28, 2003, and is hereby incorporated byreference, also discloses various embodiments of an absorbable matrixthat may be utilized with various embodiments of the third aspect of thefirst version of the present invention. It is to be noted, however, thatwound packing means 278 may not be utilized in other embodiments of thisthird aspect of the first version of the invention.

In the embodiment of the third aspect of the first version of theinvention illustrated in FIG. 3, the wound treatment device 215 is alsocomprised of a suction drain 245 and suction drain connection means,which are described in more detail below, to operably connect thereduced pressure supply means 240 to the suction drain 245 so that thesuction drain 245 is in fluid communication with the reduced pressuresupply means 240 and reduced pressure is supplied to the volume underthe flexible overlay 220 in the area of the wound 260 by means of thesuction drain 245. In this embodiment, the suction drain 245 is furthercomprised of a bottom drain portion 245 a extending into the area of thewound 260 under the impermeable overlay 220 from a top drain portion 245b positioned within the port 227. In various embodiments, the top drainportion 245 b may be permanently or removably attached to the interiorsurface of the opening 228 of the port 227 using any suitable means,such as an adhesive, or by the top drain portion 245 b having a shapeadapted so that all or a portion of it fits tightly against all or aportion of the interior surface of the opening 228 in the port 227. Itis to be noted that the top drain portion 245 b must be sufficientlysealed against the surface of the port 227 in a manner so that reducedpressure can be maintained in the volume under the impermeable overlay220 in the area of the wound 260. In the embodiment illustrated in FIG.3, the top drain portion 245 b and the bottom drain portion 245 a of thesuction drain 245 are comprised of polymer tubing that is flexibleenough to allow the tubing to easily bend, but rigid enough to preventthe tubing from collapsing during use. In other embodiments, portions ofthe top drain portion 245 b and the bottom drain portion 245 a of thesuction drain 245 may be comprised of other materials, such as flexibleor semi-rigid polymers, plastics, rubber, silicone, or combinations ofsuch materials. In yet other embodiments, the suction drain 245 may havedifferent cross-sectional shapes, such as elliptical, square,rectangular, pentagonal, hexagonal, or other shapes, as long as thesuction drain 245 is adapted to provide an approximately hermetic sealwith the port 227, as described in more detail above. In still otherembodiments, the bottom drain portion 245 a of the suction drain 245 maybe further comprised of wound suction means that may be used to removedebris, exudate and other matter from the wound 260. In the embodimentillustrated in FIG. 3, the wound suction means is comprised of a distalend portion 245 a′ of the tubing comprising the bottom drain portion 245a having a plurality of perforations 245 a″ in the surface of the distalend portion 245 a′. In other embodiments, the distal end portion 245 a′of the bottom drain portion 245 a may have almost any shape orcombination of shapes (e.g., circular, elliptical, square, pentagonal,or hexagonal), including a shape different from the remaining portion ofthe bottom drain portion 245 a, may be of almost any size relative tothe remaining bottom drain portion 245 a (e.g., may be longer or shorterthan the remaining bottom drain portion 245 a or have a cross-sectionsmaller or larger than the remaining bottom drain portion 245 a, orboth), may have more or fewer perforations 245 a″, may have differentsizes and shapes of perforations 245 a″, may extend along differentportions of the bottom drain portion 245 a, and may be constructed inwhole or in part of materials that are not flexible. In embodiments thathave a distal end portion 245 a′, the distal end portion 245 a′ may beattached to the remaining portion of the bottom drain portion 245 a inalmost any manner, as long as the remaining bottom drain portion 245 ais in fluid communication with the wound suction means 245 a′. Examplesinclude an adhesive in some embodiments and a fastening collar in otherembodiments. In still other embodiments, the distal end portion 245 a′may be fused or welded to the remaining portion of the bottom drainportion 245 a. In yet other embodiments, the distal end portion 245 a′and the remaining portion of the bottom drain portion 245 a may befabricated as a single piece.

In some embodiments of this first version of the invention, asillustrated in FIG. 3, the top drain portion 245 b may extend beyond thetop of the port 227 into the area outside the volume of the flexibleoverlay 220. In some of these embodiments, as is also illustrated inFIG. 3, the suction drain connection means, which may be used toremovably connect the reduced pressure supply means 240 to the top drainportion 245 b of the suction drain 245 is a variable descending diameteradapter 246 (commonly referred to as a “Christmas tree” adapter) that isplaced into the interior volume of the top drain portion 245 b at itsdistal end. In other embodiments, the suction drain connection means maybe clamps, fastening collars, or other fasteners or combinationsthereof. In yet other embodiments, the top drain portion 245 b may befused or welded to the reduced pressure supply means 240. In still otherembodiments, the top drain portion 245 b and the portion of the reducedpressure supply means 240 adjacent to the top drain portion 245 b may befabricated as a single piece. In other embodiments, the top drainportion 245 b may not extend beyond the top of the port 227 and thereduced pressure supply means 240 may connect directly to the port 227using any suitable means, such as an adhesive, welding, fusing, clamps,collars or other fasteners, or any combination of such means.

In the embodiment of this third aspect of the first version of theinvention illustrated in FIG. 3, the distal end portion 245 a′ of thesuction drain 245 extends into the interior volume of the wound packingmeans 278. In this embodiment, the wound packing means 278 and thesuction drain 245 may be fabricated by snaking the distal end portion245 a′ of the suction drain 245 through an internal passageway in thewound packing means 278, such as by pulling the distal end portion 245a′ of the suction drain 245 through the passageway using forceps.Alternatively, the wound packing means 278 and the suction drain 245 maybe manufactured as a single piece in sterile conditions and then bestored in an aseptic package until ready for use. In other embodiments,the distal end portion 245 a′ of the suction drain 245 may be placedadjacent or close to the wound packing means 278 in the area of thewound 260. The preferred means of placement of the suction drain 245relative to the wound packing means 278 is dependent upon the type ofwound 260, the wound packing means 278, and the type of treatmentdesired. Referring to FIG. 3 as an example, it is therefore to be notedthat in some embodiments of this third aspect of the first version ofthe invention, the wound treatment device 215 may utilize a suctiondrain 245 without utilizing wound packing means 278, while in otherembodiments a suction drain 245 may be utilized with wound packing means278. In addition, in other embodiments of this first version of theinvention, the wound treatment device 215 may utilize wound packingmeans 278 without utilizing a suction drain 245, while in otherembodiments wound packing means 278 may be utilized with a suction drain245.

In the embodiment of the first version of the invention illustrated inFIG. 3, the vacuum system 250, which in conjunction with the woundtreatment device 215 also represents a fourth aspect of this firstversion of the invention, is generally comprised of a suction bulb 281having an inlet port 282 and an outlet port 283, a bulb connectiontubing member 284, an exhaust tubing member 285, an exhaust controlvalve 286, a filter 287, and a supplemental vacuum system (illustratedschematically and generally designated 250 a). In this embodiment, thesuction bulb 281 is a hollow sphere that may be used to produce a supplyof reduced pressure for use with the wound treatment device 215. Inaddition, the suction bulb 281 may also be used to receive and storefluid aspirated from the wound 260. The inlet port 282 of the suctionbulb 281 is connected to one end of the bulb connection tubing member284, which is also the reduced pressure supply means 240 in thisembodiment. The connection tubing member 284 is connected by suctiondrain connection means to the top drain portion 245 b at its other endin a manner so that the interior volume of the suction bulb 281 is influid communication with the suction drain 245. In this embodiment, thebulb connection tubing member 284 is sufficiently flexible to permitmovement of the bulb connection tubing member 284, but is sufficientlyrigid to resist constriction when reduced pressure is supplied to thesuction drain 245 or when the location of the wound 260 is such that thepatient must sit or lie upon the bulb connection tubing member 284 orupon the wound treatment device 215. The outlet port 283 of the suctionbulb 281 is connected to the exhaust tubing member 285. In thisembodiment, the exhaust tubing member 285 is sufficiently flexible topermit movement of the exhaust tubing member 285, but is sufficientlyrigid to resist constriction when reduced pressure is supplied to thesuction drain 245. The inlet port 282 of the suction bulb 281 may beconnected to the bulb connection tubing member 284 and the outlet port283 of the suction bulb 281 may be connected to the exhaust tubingmember 285 using any suitable means, such as by welding, fusing,adhesives, clamps, or any combination of such means. In addition, insome embodiments, which are the preferred embodiments, the suction bulb281, the bulb connection tubing member 284, and the exhaust tubingmember 285 may be fabricated as a single piece. In the illustratedembodiment, the exhaust control valve 286 and the filter 287 areoperably connected to the exhaust tubing member 285. In this embodiment,the exhaust control valve 286 is used to regulate the flow of fluids(gases and liquids) to and from the suction bulb 281 and thesupplemental vacuum system 250 a. In embodiments of the invention thatdo not have a supplemental vacuum system 250 a, the exhaust controlvalve 286 regulates flow of fluids to and from the suction bulb 281 andthe outside atmosphere. Generally, the exhaust control valve 286 allowsfluids to flow out of the suction bulb 281 through the outlet port 283,but not to flow in the reverse direction unless permitted by the user ofthe appliance 210. Any type of flow control valve may be used as theexhaust control valve 286, as long as the valve is capable of operatingin the anticipated environment involving reduced pressure and wound 260exudate. Such valves are well known in the relevant art, such as sprungand unsprung flapper-type valves and disc-type valves. In thisembodiment, the filter 287 is operably attached to the exhaust tubingmember 285 between the outlet port 283 of the suction bulb 281 and theexhaust control valve 286. The filter 287 prevents potentiallypathogenic microbes or aerosols from contaminating the exhaust controlvalve 286 (and supplemental vacuum system 250 a), and then being ventedto atmosphere. The filter 287 may be any suitable type of filter, suchas a micropore filter. In other embodiments, the filter 287 may also bea hydrophobic filter that prevents any exudate from the wound 260 fromcontaminating the exhaust control valve 286 (and the supplemental vacuumsystem 250 a) and then being vented to atmosphere. In still otherembodiments, the filter 287 may perform both functions. It is to benoted, however, that the outlet port 283, the exhaust control valve 286,the filter 287, or any combination of the exhaust control valve 286 andthe filter 287, need not be utilized in connection with the vacuumsystem 250 in other embodiments of the invention.

In some embodiments of these third and forth aspects of the firstversion of the invention illustrated in FIG. 3 that do not utilize asupplemental vacuum system 250 a, the suction bulb 281 may be used toproduce a supply of reduced pressure in the following manner. First, theuser of the appliance 210 appropriately seals all of the component partsof the appliance 210 in the manner described herein. For example, theimpermeable overlay 220 is sealed (or placed adjacent) to the body 170and the suction drain 245 is sealed to the bulb connection tubing member284 and the surface of the port 227. The user then opens the exhaustcontrol valve 286 and applies force to the outside surface of thesuction bulb 281, deforming it in a manner that causes its interiorvolume to be reduced. When the suction bulb 281 is deformed, the gas inthe interior volume is expelled to atmosphere through the outlet port283, the exhaust tubing member 285, the filter 287, and the exhaustcontrol valve 286. The user then closes the exhaust control valve 286and releases the force on the suction bulb 286. The suction bulb 281then expands, drawing fluid from the area of the wound 260 under thewound treatment device 215 into the suction bulb 281 through the suctiondrain 245 and causing the pressure in such area to decrease. To releasethe reduced pressure, the user of the appliance 210 may open the exhaustcontrol valve 286, allowing atmospheric air into the interior volume ofthe suction bulb 281. The level of reduced pressure may also beregulated by momentarily opening the exhaust control valve 286.

The suction bulb 281 may be constructed of almost any fluid impermeableflexible or semi-rigid material that is suitable for medical use andthat can be readily deformed by application of pressure to the outsidesurface of the suction bulb 281 by users of the appliance 210 and stillreturn to its original shape upon release of the pressure. For example,the suction bulb 281 may be constructed of rubber, neoprene, silicone,or other flexible or semi-rigid polymers, or any combination of all suchmaterials. In addition, the suction bulb 281 may be of almost any shape,such as cubical, ellipsoidal, or polygonal. The suction bulb 281 mayalso be of varying size depending upon the anticipated use of thesuction bulb 281, the size of the wound treatment device 215, use of asupplemental vacuum system 250 a, the level of reduced pressure desired,and the preference of the user of the appliance 210. In the embodimentof the invention illustrated in FIG. 3, the supplemental vacuum system250 a is connected to the exhaust tubing member 285 and is used toprovide a supplemental supply of reduced pressure to the suction bulb281 and wound treatment device 215. In this embodiment, the supplementalvacuum system 250 a may have substantially the same structure, features,characteristics and operation of the various embodiments of the vacuumsystem 50 of the first version of the invention described above andillustrated in connection with FIG. 2A and FIG. 2B. It is to be noted,however, that the supplemental vacuum system 250 a need not be used inconnection with the vacuum system 280 in other embodiments of theinvention.

Except as described below, the wound treatment appliance 210 describedabove and illustrated in connection with FIG. 3 may generally be used ina manner similar to the wound treatment appliance 110 described aboveand illustrated in connection with FIG. 2A and FIG. 2B. As a result,except as described below, the example of how the embodiment of thewound treatment appliance 110 and the flexible overlay 120 describedabove and illustrated in connection FIG. 2A may be used in treatment ofa wound 160 also applies to the embodiment of the appliance 210 of thethird aspect of the first version of the invention described above andillustrated in connection with FIG. 3. In the case of the embodimentillustrated in FIG. 3, however, the wound packing means 278 is placedinto the wound 260 prior to placement of the flexible overlay 220 overthe portion of the wound 260 to be treated. In addition, the flexibleoverlay 220 is placed over the wound packing means 278. In embodimentswhere the distal end portion 245 a′ of a suction drain 245 is placedinto the interior volume of, or adjacent to, the wound packing means278, the distal end portion 245 a′ of the suction drain 245 is alsoplaced in the appropriate position before the flexible overlay 220 isplaced over the wound 260. In embodiments utilizing a suction drain 245without wound packing means 278, the suction drain 245 is installed inthe flexible overlay 220 before the flexible overlay 220 is placed overthe wound 260.

Another embodiment of the first version of the invention is the woundtreatment appliance 310 illustrated in FIG. 4. FIG. 4 also illustratesanother example of how the embodiment of the flexible overlay 20described above and illustrated in connection with FIG. 1A may be usedto provide reduced pressure treatment for a wound 360 on the body 370 ofa patient. In this embodiment, the wound treatment appliance 310 iscomprised of a flexible overlay 320 and a vacuum system, generallydesignated 350, that is operably connected to, and provides a supply ofreduced pressure to, the flexible overlay 320. In addition, in thisembodiment, the vacuum system 350 is further comprised of a reducedpressure supply source, generally designated 330, which is described inmore detail below, and reduced pressure supply means, generallydesignated 340, which are described in more detail below. In thisembodiment, the reduced pressure supply means 340 are used to connectthe reduced pressure supply source 330 to the flexible overlay 320 in amanner so that reduced pressure is supplied to the area under theflexible overlay 320, as described in more detail below. In theembodiment of the first version of the invention illustrated in FIG. 4,the flexible overlay 320 has substantially the same structure, featuresand characteristics as the flexible overlay 20 described above andillustrated in connection with FIG. 1A. It is to be noted, however, thatin other embodiments of this first version of the invention, theflexible overlay 320 may have substantially the same structure, featuresand characteristics as any embodiment of all of the flexible overlays20, 20 a, 20 b, 20 c of the first version of the invention describedabove and illustrated in connection with FIG. 1A, FIG. 1B, FIG. 1C, andFIG. 1D, respectively. In this example, the flexible overlay 320 isplaced over and encloses the entire wound 360, which is at the distalend of an amputated limb. It is to be noted that in other embodiments,the appliance 310 may also be comprised of tissue protection means 375,which may be substantially the same as the tissue protection means 175of the first version of the invention described above and illustrated inconnection with FIG. 2A. In other embodiments, the appliance 310 mayalso be comprised of wound packing means (not illustrated), which may besubstantially the same as the wound packing means 278 of the firstversion of the invention described above and illustrated in connectionwith FIG. 3.

In the embodiment of the first version of the invention illustrated inFIG. 4, the reduced pressure supply source 330 of the vacuum system 350,which produces a source of reduced pressure or suction that is suppliedto the flexible overlay 320, includes a small, portable vacuum pump 331,a filter 333, and a power source (not illustrated) that is containedwithin the housing for the portable vacuum pump 331. In the illustratedembodiment, predetermined amounts of suction or reduced pressure areproduced by the portable vacuum pump 331. The portable vacuum pump 331is preferably controlled by a control device (not illustrated) that isalso located within the housing for the portable vacuum pump 331, whichmay provide substantially the same functions as the control device 132of the first version of the invention described above and illustrated inconnection with FIG. 2A and FIG. 2B. Except for its smaller size, theportable vacuum pump 331 may operate in substantially the same manner asthe vacuum pump 131 of the first version of the invention describedabove and illustrated in connection with FIG. 2A and FIG. 2B. In theembodiment illustrated in FIG. 4, the filter 333 may have the samestructure, features, characteristics and operation, and providesubstantially the same functions, as the filter 133 of the first versionof the invention described above and illustrated in connection with FIG.2A and FIG. 2B. The power source may be any source of energy currentlyknown in the art or that may be developed in the art in the future thatmay be used to power the portable vacuum pump 331. For example, in someembodiments, the power source may be a fuel cell, battery or connectionto a standard electrical outlet. In the illustrated embodiment, thefilter 333 is rigidly connected to the portable vacuum pump 331. It isto be noted that in other embodiments of the first version of theinvention, the reduced pressure supply source 330 may not have a filter333.

In the embodiment of the first version of the invention illustrated inFIG. 4, the reduced pressure supply means 340 of the vacuum system 350,which is used to connect the reduced pressure supply source 330 to aport 327 on the flexible overlay 320 so that reduced pressure issupplied to the area of the wound 360 under the flexible overlay 320, iscomprised of at least one tubing member 341. In this embodiment, the atleast one tubing member 341 is a rigid tubing member. In otherembodiments, the at least one tubing member 341 may be sufficientlyflexible to permit movement of the at least one tubing member 341, butis sufficiently rigid to resist constriction when reduced pressure issupplied to the port 327 or when the location of the wound 360 is suchthat the patient must sit or lie upon the at least one tubing member 341or upon the flexible overlay 320. In the embodiment illustrated in FIG.4, the at least one tubing member 341 is connected to the port 327 byinserting one end of the at least one tubing member 341 into an opening328 in the port 484 and sealing (such as with an adhesive) the at leastone tubing member 341 to the port 327. It is to be noted that in otherembodiments, the at least one tubing member 341 may be connected to theport 327 using any suitable means currently known in the relevant art ordeveloped in the relevant art in the future. Examples include thesuction drain connection means of the first version of the inventiondiscussed above and illustrated in connection with FIG. 3. Similar meansmay be used to connect the other end of the at least one tubing member341 to the reduced pressure supply source 330 providing the reducedpressure. In other embodiments of this first version of the invention,the reduced pressure supply means 340 may further comprise a fluidcollection system (not illustrated), which may generally have the samestructure, features, characteristics and operation, and perform the samefunctions, as the fluid collection system 142 of the first version ofthe invention described above and illustrated in connection with FIG. 2Aand FIG. 2B.

An embodiment of a second version of the invention is the woundtreatment appliance 410 illustrated in FIG. 5. In this embodiment, theappliance 410 is comprised of a wound treatment device 415, which isfurther comprised of a flexible overlay 420, a collection chamber 490 toreceive and hold fluid aspirated from the wound 460, collection chamberattachment means to operably attach the collection chamber 490 to theoverlay 420, as described in more detail below, and reduced pressuresupply means, generally designated 440, which are described in moredetail below. In this embodiment, the flexible overlay 420 is adapted tobe placed over and enclose all or a portion of the wound 460 in the samemanner as the flexible overlay 20 described in detail above andillustrated in connection with FIG. 1A. It is to be noted, however, thatthe flexible overlay 420 illustrated in FIG. 5 is shown in position onthe body 470 over the wound 460, but not in its collapsed state. In theillustrated embodiment, and except as described in more detail below,the flexible overlay 420 has substantially the same structure, featuresand characteristics as the flexible overlay 20 described in detail aboveand illustrated in connection with FIG. 1A. In the various embodimentsof this second version of the invention, except as described in moredetail below, the flexible overlay 420 may have substantially the samestructure, features, characteristics and operation as the embodiments ofthe flexible overlays 20, 20 a, 20 b, 20 c, 120, 220 described in moredetail above and illustrated in connection with FIG. 1A, FIG. 1B, FIG.1C, FIG. 1D, FIG. 2A, and FIG. 3, respectively. In the illustratedembodiment, reduced pressure supply means, generally designated 440,which are described in more detail below, are used to operably connectthe collection chamber 490 to a reduced pressure supply source,generally designated 430, which is described in more detail below, thatprovides a supply of reduced pressure to the collection chamber 490, sothat the volume within the collection chamber 490 and under the flexibleoverlay 420 in the area of the wound 460 to be treated are supplied withreduced pressure by the reduced pressure supply source 430. Together,the reduced pressure supply means 440 and the reduced pressure supplysource 430 comprise a vacuum system, generally designated 450. In thevarious embodiments of this second version of the invention, except asdescribed in more detail below, the reduced pressure supply means 440used to connect the reduced pressure supply source 430 to the collectionchamber 490 may have substantially the same structure, features,characteristics and operation as the reduced pressure supply means 140,240, 340 described above and illustrated in connection with FIG. 2A,FIG. 2B, FIG. 3, and FIG. 4, respectively. In addition, in the variousembodiments of this second version of the invention, except as describedin more detail below, the reduced pressure supply source 430 used toprovide the supply of reduced pressure to the collection chamber 490 mayhave substantially the same structure, features, characteristics andoperation as the reduced pressure supply source 130, 280, 330 describedabove and illustrated in connection with FIG. 2A, FIG. 2B, FIG. 3, andFIG. 4, respectively.

In the embodiment of the appliance 410 illustrated in FIG. 5, thecollection chamber 490 is approximately cylindrical in shape. In otherembodiments, the collection chamber 490 may have other shapes. Forexample, the collection chamber may be shaped approximately as a sphere,ellipsoid, cube, polyhedron, or other shape or combination of suchshapes, as long as the collection chamber 490 has an interior volume toreceive and hold fluid aspirated from the wound 460. The collectionchamber 490 may also be of almost any size. For example, the collectionchamber 490 may be relatively small where the wound 460 is expected toaspirate only a small volume of fluid. On the other hand, the collectionchamber 490 may be relatively large where it is expected that the wound460 will aspirate a large volume of fluid. As a result, the preferredsize of the collection chamber 490 is dependent upon the size of thewound 460 to be treated, the size of the flexible overlay 420, the typeof wound 460 to be treated, and the preference of the user of theappliance 410. In the various embodiments of this second version of theinvention, the collection chamber 490 may be comprised of almost anymedical grade material that is currently known in the art or that may bedeveloped in the art in the future, as long as such material isfluid-impermeable and suitable for purposes of wound treatment (e.g.,can be sterilized and does not absorb significant amounts of wound 460exudate). For example, the collection chamber 490 may be comprised ofrubber (including neoprene) and polymer materials, such as silicone,silicone blends, silicon substitutes, polyvinyl chloride,polycarbonates, polyester-polycarbonate blends, or a similar polymer, orcombinations of all such materials. It is to be noted that thecollection chamber 490 may have a rigid or semi-rigid structure in someembodiments. In other embodiments, the collection chamber 490 may bemore flexible so that it can be squeezed in a manner similar to thesuction bulb 281, as described above and illustrated in connection withFIG. 3. Although the collection chamber 490 may be constructed of amaterial different from the material comprising the flexible overlay 420in various embodiments of the invention, the collection chamber 490 ispreferably constructed from the same material comprising the flexibleoverlay 420. The collection chamber 490 may be constructed using anysuitable means currently known in the art or that may be developed inthe art in the future. For example, a collection chamber 490 constructedof silicone may be manufactured by means of injection molding.

In the various embodiments of this second version of the invention, thecollection chamber attachment means operably attaches the collectionchamber 490 to the flexible overlay 420 in a manner so that exudate andreduced pressure are permitted to flow between the collection chamber490 and the volume under the flexible overlay 420 in the area of thewound 460. Also, in the various embodiments of the second version of theinvention, as illustrated by the appliance 410 in FIG. 5, the collectionchamber 490 is positioned approximately adjacent to the flexible overlay420 on the side of the flexible overlay 420 opposite the wound 460.Although the collection chamber 490 and the collection chamberattachment means are positioned approximately at the apex of theflexible overlay 420 in the illustrated embodiment, in other embodimentsthe collection chamber 490 and collection chamber attachment means maybe positioned at almost any location on the surface of the impermeableoverlay 420 opposite the wound 460, as long as the collection chamber490 and collection chamber attachment means do not materially interferewith the operation of the flexible overlay 420. As illustrated in FIG.5, the collection chamber attachment means may be a rigid or semi-rigidconnecting member 491 between the collection chamber 490 and theflexible overlay 420. In this embodiment, the connecting member 491 isapproximately cylindrical in shape and has a port 492 therein, which isalso approximately cylindrical in shape and extends between thecollection chamber 490 and the flexible overlay 420 so that fluids canflow between the collection chamber 490 and the flexible overlay 420. Inother embodiments, the connecting member 491 and the port 492 may be ofalmost any shape or combination of shapes. For example, the connectingmember 491 and the port 492 may be shaped approximately as a sphere,ellipsoid, cube, polygon, paraboloid, or any other shape or combinationof shapes, as long as the connecting member 491 provides a rigid orsemi-rigid connection between the collection chamber 490 and theflexible overlay 420 that is adequate to support the collection chamber490 when it is filled with exudate from the wound 460, and the port 492is of a size and shape adequate to allow the flow of exudate from thewound 460 between the collection chamber 490 and the flexible overlay420. For example, the collection chamber 490 in some embodiments mayhave approximately the same outside diameter as the connecting member491, as illustrated by the phantom lines 493 in FIG. 5. The connectingmember 491 may generally be constructed of any material that is suitablefor construction of the collection chamber 490 or the flexible overlay420, and is preferably constructed from the same materials as thecollection chamber 490 and the flexible overlay 420. In variousembodiments, the collection chamber 490 and the flexible overlay 420 maybe connected to the connecting member 491 using any suitable means, suchas by adhesives, welding, fusing, clamps, and other fastening means orcombinations of such means. In yet other embodiments, the collectionchamber 490, the flexible overlay 420, and the connecting member 491 maybe fabricated as a single piece. In still other embodiments, one or moreof the connections between the collection chamber 490, the flexibleoverlay 420, and the connecting member 491 may provide for removing onecomponent from another to empty fluid from the collection chamber 490.For example, the collection chamber 490, the flexible overlay 420, andthe connecting member 491 may each be threaded at their points ofconnection so that they can be screwed together and then unscrewed whendesired. In still other embodiments, the collection chamber 490 and theflexible overlay 420 may be directly connected together without aconnecting member 491, as long as the connection allows fluid to flowbetween the collection chamber 490 and the flexible overlay 420. Suchconnection may be made using any of the means described above in thisparagraph.

In some embodiments of this second version of the invention, asillustrated in FIG. 5, the connecting member 491, as the collectionchamber attachment means, may be further comprised of a flow controlmeans, which is described in more detail below, operably positionedbetween the collection chamber 490 and the flexible overlay 420. Inthese embodiments, the flow control means permits fluid aspirated fromthe wound 460 to flow from the volume under the flexible overlay 420 inthe area of the wound 460 through the port 492 into the collectionchamber 490, but not in the opposite direction. In the illustratedembodiment, the flow control means is comprised of a flapper-type valve494. In this embodiment, the valve 494 has two flapper members 494 athat are hinged at their distal end to a portion of the connectingmember 491, and the flapper members 494 a are of a shape and sizeadapted to substantially close the port 492 when they are positioned inthe closed position. In other embodiments, the flow control means may becomprised of a disc-type valve, wherein the disc of the valve moves withthe flow of fluids and contacts a seat disposed around the perimeter ofthe port when the flow of fluids is misdirected, so that the port issealed closed and prevents fluid flow in the wrong direction. In someembodiments, as illustrated in FIG. 5, the collection chamber 490 may befurther comprised of a shroud 495 (illustrated by the phantom lines)that extends from a portion of the collection chamber 490 to theflexible overlay 420. In these embodiments, the shroud 495 isapproximately tubular in shape. In other embodiments, the shroud 495 mayhave other shapes. The shroud 495 generally provides additional supportfor the collection chamber 490 and may also provide for a moreaesthetically pleasing appearance for the appliance 410. In addition, inthe embodiment of the appliance 410 illustrated in FIG. 5, the reducedpressure supply means 440 is connected to the collection chamber 490 bymeans of a stopper 445 adapted to fit into an opening 496 in thecollection chamber 490. The stopper 445 forms a seal with the portion ofthe collection chamber 490 adjacent to the opening 496 so that reducedpressure can be maintained within the interior volume of the collectionchamber 490. In this embodiment, the reduced pressure supply means iscomprised of a tubular member 441 that is positioned in a port 446 inthe stopper 445 at one end and is connected to the reduced pressuresupply source 430 at the other end.

The embodiment of the appliance 410 illustrated in FIG. 5 may be used totreat a wound 460 on a body 470 using a method comprising the followingsteps. First, the wound treatment device 415 is positioned on the body470 over the area of the wound 460 to be treated. Next, the vacuumsystem 450 is operably connected to the collection chamber 490. Theflexible overlay 420 may then be collapsed in the approximate directionof the wound 460 when reduced pressure is supplied to the volume underthe flexible overlay 420 in the area of the wound 460 so that anapproximately hermetic seal (as illustrated and described in more detailabove in connection with FIG. 2A) is formed between the flexible overlay420 and the body 470 in the area of the wound 460. Next, reducedpressure is maintained in the volume of the flexible overlay 420 in thearea of the wound 460 until the area of the wound 460 being treated hasprogressed toward a selected stage of healing. In other embodiments, themethod may further comprise the step of placing tissue protection means475, which may be substantially the same as the tissue protection means175, as described above and illustrated in connection with FIG. 2A, onthe tissue 471 of the body 470 that is to be approximately adjacent tothe flexible overlay 420, such step being performed prior to positioningthe flexible overlay 420 over the area of the wound 460 to be treated.In yet other embodiments, the method further comprises the step ofplacing wound packing means (not illustrated), which may besubstantially the same as the wound packing means 278, as describedabove and illustrated in connection with FIG. 3, between the wound 460and the impermeable overlay 420 in the area of the wound 460 to betreated, such step being performed prior to positioning the impermeableoverlay 420 over the area of the wound 460 to be treated. In still otherembodiments, the reduced pressure under the flexible overlay 420 in thearea of the wound 460 is in the range from approximately 20 mm of Hgbelow atmospheric pressure to approximately 125 mm of Hg belowatmospheric pressure. In other embodiments, the reduced pressure isapplied in a cyclic nature, the cyclic nature providing alternating timeperiods of application of reduced pressure and without application ofreduced pressure. In yet other embodiments, the method is furthercomprised of the step of emptying any fluid collected in the collectionchamber 490. This step may be performed after the flexible overlay 420is collapsed in the approximate direction of the wound 460 and may alsobe performed before or after the area of the wound 460 being treated hasprogressed toward a selected stage of healing.

Another embodiment of the second version of the invention is the woundtreatment appliance 510 illustrated in FIG. 6. In this embodiment, theappliance 510 is comprised of a flexible overlay 520, a collectionchamber 590 to receive and hold fluid aspirated from a wound (notshown), collection chamber attachment means to operably attach thecollection chamber 590 to the flexible overlay 520, as described in moredetail below, and reduced pressure supply means, generally designated540, which are described in more detail below. In this embodiment, theflexible overlay 520 is adapted to be placed over and enclose all or aportion of a wound in the same manner as the flexible overlay 20 adescribed in detail above and illustrated in connection with FIG. 1B. Itis to be noted that the flexible overlay 520 illustrated in FIG. 6 isnot shown in its collapsed state. In the illustrated embodiment, andexcept as described in more detail below, the flexible overlay 520 hassubstantially the same structure, features and characteristics as theflexible overlay 20 a described in detail above and illustrated inconnection with FIG. 1B. In other embodiments, the flexible overlay 520may be of other shapes and have other features. For example, theflexible overlay 520 may be of the shape and have the featuresillustrated and described above in connection with the appliance 10 band 10 c of FIG. 1C and FIG. 1D, respectively. In the embodimentillustrated in FIG. 6, the reduced pressure supply means 540, which aredescribed in more detail below, may be used to operably connect thecollection chamber 590 to a reduced pressure supply source (not shown),which is described in more detail below, that provides a supply ofreduced pressure to the collection chamber 590, so that the volumewithin the collection chamber 590 and under the flexible overlay 520 inthe area of the wound to be treated are supplied with reduced pressureby the reduced pressure supply source. Together, the reduced pressuresupply means 540 and the reduced pressure supply source comprise avacuum system, generally designated 550. In this embodiment of thesecond version of the invention, except as described in more detailbelow, the reduced pressure supply means 540 used to connect the reducedpressure supply source to the collection chamber 590 may havesubstantially the same structure, features, characteristics andoperation as the reduced pressure supply means 140, 240, 340 describedabove and illustrated in connection with FIG. 2A, FIG. 2B, FIG. 3, andFIG. 4, respectively. In addition, in this embodiment of the secondversion of the invention, except as described in more detail below, thereduced pressure supply source used to provide the supply of reducedpressure to the collection chamber 590 may have substantially the samestructure, features, characteristics and operation as the reducedpressure supply source 130, 280, 330 described above and illustrated inconnection with FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4, respectively. Theembodiment of the appliance 510 illustrated in FIG. 6 may be used totreat a wound on a body using substantially the same method describedabove in connection with the appliance 410 illustrated in FIG. 5.

In the embodiment illustrated in FIG. 6, the collection chamber 590 ispositioned approximately adjacent to the flexible overlay 520 on theside of the flexible overlay 520 opposite the wound. In this embodiment,the collection chamber attachment means, as described in more detailbelow, is comprised of a membrane 591. In this embodiment, the membrane591 acts as a barrier separating the collection chamber 590 and theflexible overlay 520, so that the membrane 591 acts as a portion of thesurface of the collection chamber 590 and a portion of the surface ofthe flexible overlay 520. In addition, the membrane 591 has at least oneport 592 therein so that the volume within the collection chamber 590 isin fluid communication with the volume under the flexible overlay 520 inthe area of the wound. It is to be noted that there may be more than oneport 592 in other embodiments. The number of ports 492 is generallydependent upon the size and shape of the collection chamber 590, thesize and shape of the impermeable flexible overlay 520, the anticipatedamount of exudate to be aspirated from the wound, the level of reducedpressure to be utilized, and the individual preference of the user ofthe appliance 510. In embodiments where the flexible overlay 520 has anapproximately elongated conical shape, as illustrated in FIG. 6, theflexible overlay 520 may have a base end opening 521 and a top endopening 524 opposite the base end opening 521. In these embodiments, thebase end opening 521 may have an either approximately circular shape orapproximately elliptical shape sized to be placed over and enclose thearea of the wound to be treated. The top end opening 524 may have eitheran approximately circular shape or approximately elliptical shape. Inthe illustrated embodiments, the membrane 591 is adapted to be of thesame shape and size as the top end opening 524 and the membrane 591 ispositioned so that it is attached to the entire perimeter of the top endopening 524 and covers the entire top end opening 524. The membrane 591may be attached to the perimeter of the top end opening 524 by anysuitable means currently known in the relevant art or developed in theart in the future. Examples of such means include welding or fusing themembrane 591 to the perimeter of the top end opening 524. Alternatively,the membrane 591 may be fabricated as a single piece with the flexibleoverlay 520.

In the embodiment of the appliance 510 illustrated in FIG. 6, thecollection chamber 590 has an approximately elongated conical shape, achamber bottom end opening 593, and a reduced pressure supply port 596positioned at the apex of the collection chamber 590 opposite thechamber bottom end opening 593. The reduced pressure supply port 596 maybe used to operably connect the reduced pressure supply means 540 to thecollection chamber 590. In some embodiments, a micropore or hydrophobicfilter or both (not shown) may be operably positioned within the reducedpressure supply port 596 or the connection with the reduced pressuresupply means 540 to retain the exudate from the wound within thecollection container 590 or to prevent exudate from contaminatingportions of the vacuum system 550, or both. In the illustratedembodiment, the chamber bottom end opening 593 is adapted to be ofapproximately the same size and shape as the top end opening 524 of theimpermeable flexible overlay 520. In other embodiments, the collectionchamber 590 may be of other shapes and sizes and its bottom end opening593 may not necessarily be of the same size and shape as the top endopening 524 of the flexible overlay 520. In all embodiments, however,the collection chamber 590 is attached to the membrane 591 in a mannerso that the membrane 591 acts as a portion of the surface of thecollection chamber 590 and so that the volume within the collectionchamber 590 is airtight, except for the at least one port 592 and thereduced pressure supply port 596. In the preferred embodiment, thecollection chamber 590 and the flexible overlay 520 have the shapesillustrated in FIG. 6. The membrane 591 may be attached to the perimeterof the chamber bottom end opening 593 by any suitable means currentlyknown in the relevant art or developed in the art in the future.Examples of such means include welding or fusing the membrane 591 to theperimeter of the chamber bottom end opening 593. Alternatively, themembrane 591 or the flexible overlay 520, or both, may be fabricated asa single piece with the collection chamber 590. The preferred shapes andsizes of the collection chamber 590 and the flexible overlay 520 aredependent upon the size and type of wound to be treated, the area of thebody on which the wound is positioned, the level of reduced pressure tobe utilized, the amount of collapse of the flexible overlay 520 desired,and the preference of the user of the appliance 510. In this embodimentof the second version of the invention, the collection chamber 590 maybe comprised of almost any medical grade material that is currentlyknown in the art or that may be developed in the art in the future, aslong as such material is fluid-impermeable and suitable for purposes ofwound treatment (e.g., can be sterilized and does not absorb significantamounts of wound exudate). For example, the collection chamber 590 maybe comprised of rubber (including neoprene) and flexible polymermaterials, such as silicone, silicone blends, silicone substitutes,polyvinyl chloride, polycarbonates, polyester-polycarbonate blends, or asimilar polymer, or combinations of all such materials. It is to benoted that the collection chamber 590 may have a rigid or semi-rigidstructure in some embodiments. In other embodiments, the collectionchamber 590 may be more flexible so that it can be squeezed in a mannersimilar to the suction bulb 281, as described above and illustrated inconnection with FIG. 3. Although the collection chamber 590 may beconstructed of a material different from the material comprising theflexible overlay 520 in various embodiments of the invention, thecollection chamber 590 is preferably constructed from the same materialcomprising the flexible overlay 520. The collection chamber 590 may beconstructed using any suitable means currently known in the art or thatmay be developed in the art in the future. For example, a collectionchamber 590 constructed of silicone may be manufactured by means ofinjection molding.

In the embodiment of the second version of the invention illustrated inFIG. 6, the membrane 591 and its means of being sealed to the perimetersof the top end opening 524 and the chamber bottom end opening 593,together as collection chamber attachment means, operably attach thecollection chamber 590 to the impermeable overlay 520 in a manner sothat exudate and reduced pressure are permitted to flow between thecollection chamber 590 and the volume under the impermeable overlay 520in the area of the wound. In the embodiment illustrated in FIG. 6, theat least one port 592 is approximately cylindrical in shape and extendsbetween the collection chamber 590 and the flexible overlay 520 so thatfluids can flow between the collection chamber 590 and the flexibleoverlay 520. In other embodiments, the at least one port 592 may be ofalmost any shape or combination of shapes. In some embodiments of thissecond version of the invention, as illustrated in FIG. 6, the membrane591 comprising the collection chamber attachment means may be furthercomprised of a flow control means, which is described in more detailbelow, operably connected with the at least one port 592 and positionedbetween the collection chamber 590 and the flexible overlay 520. Inthese embodiments, the flow control means permits fluid aspirated fromthe wound to flow from the volume under the flexible overlay 520 in thearea of the wound 560 through the at least one port 592 into thecollection chamber 590, but not in the opposite direction. In theillustrated embodiment, the flow control means is comprised of aflapper-type valve 594. In this embodiment, the valve 594 has twoflapper members 594 a that are hinged at their distal end to a portionof the membrane 491 or supporting structure surrounding the at least oneport 492 and the flapper members 594 a are of a shape and size adaptedto substantially close the at least one port 592 when they arepositioned in the closed position. In other embodiments, the flowcontrol means may be comprised of a disc-type of valve.

1. An appliance for administering reduced pressure treatment to a woundon a body, the appliance comprising: a liquid impermeable flexibleoverlay having an opening sized to be placed over and enclose the areaof the wound to be treated, the overlay adapted to maintain reducedpressure in the volume under the flexible overlay in the area of thewound; and reduced pressure supply means supported at a top portion ofthe overlay to operably connect the flexible overlay to a reducedpressure supply source that provides a supply of reduced pressure to theflexible overlay, so that the volume under the flexible overlay in thearea of the wound to be treated is supplied with reduced pressure by thereduced pressure supply source; wherein: the overlay comprises aplurality of preformed channels formed in or affixed to the overlayextending from the reduced pressure supply means toward the opening toassist in the application of reduced pressure to the area of the woundand removal of exudate from the wound, wherein each of the plurality ofpreformed channels are joined together near the center of the flexibleoverlay; and the flexible overlay collapses in the approximate directionof the area of the wound to be treated when reduced pressure is suppliedto the volume under the flexible overlay in the area of the wound, suchcollapse causing the formation of an approximately hermetic seal betweenthe flexible overlay and the body in the area of the wound.
 2. Theappliance of claim 1, wherein the flexible overlay comprises an interiorsurface facing the area of the wound to be treated and the surface areaof the interior surface is greater than the surface area of the portionof the body to be enclosed by the flexible overlay.
 3. The appliance ofclaim 1, wherein: the flexible overlay comprises a bottom portion havingan approximately elongated conical shape, and the opening is formed atthe base of the bottom portion and has an approximately ellipticalshape.
 4. The appliance of claim 1, wherein the flexible overlay has anapproximately elongated conical shape, and the opening is formed at thebase of the bottom portion and has an approximately elliptical shape. 5.The appliance of claim 4, wherein the flexible overlay comprises a portlocated approximately at the apex of the approximately elongated conicalshape and the reduced pressure supply means is operably connected to theport.
 6. The appliance of claim 1, wherein: the flexible overlaycomprises at least three cover portions, each of such cover portionsbeing approximately triangular in shape; one point of each of the atleast three triangular-shaped cover portions are joined to form an apexof the flexible overlay; and one side of each at least threetriangular-shaped cover portions adjacent to the apex is joined to anadjacent side of another of such at least three triangular-shaped coverportions so that the bases of the at least three triangular-shaped coverportions form the opening.
 7. The appliance of claim 1, wherein theflexible overlay is approximately cup-shaped, and the flexible overlaycomprises a port located approximately at the apex of the flexibleoverlay, and the reduced pressure supply means is operably connected tothe port.
 8. The appliance of claim 1, wherein: at least one fold formsin the surface of the flexible overlay when the flexible overlaycollapses; and fluids aspirated by the wound flow along the at least onefold to the reduced pressure supply means and are removed from theflexible overlay by means of the reduced pressure supply meanscooperating with the reduced pressure supply source.
 9. The appliance ofclaim 1, further comprising supplemental sealing means to form a sealbetween the flexible overlay and the body in the area of the wound. 10.The appliance of claim 1, further comprising: a suction drain extendingfrom the reduced pressure supply means into the volume under theflexible overlay in the area of the wound; and suction drain connectingmeans to operably connect the reduced pressure supply means to thesuction drain so that the suction drain is in fluid communication withthe reduced pressure supply means and reduced pressure is supplied tothe volume under the flexible overlay in the area of the wound by meansof the suction drain.
 11. The appliance of claim 1, wherein the suctionassist means comprises at least one channel supported by flexibleoverlay.
 12. The appliance of claim 1, wherein the flexible overlaycomprises a port, and the reduced pressure supply means is operablyconnected to one side of the port, and the plurality of preformedchannels are operably connected to the other side of the port.
 13. Theappliance of claim 1, wherein the plurality of preformed channelscomprise at least one raised portion disposed on the surface of theflexible overlay.
 14. An appliance for administering reduced pressuretreatment to a wound on a body, the appliance comprising: a woundtreatment device, wherein the wound treatment device comprises a liquidimpermeable flexible overlay having a bottom opening sized to be placedover and enclose the area of the wound to be treated and adapted tomaintain reduced pressure in the area of the wound to be treated,wherein the flexible overlay comprises at least one channel formed in oraffixed to the overlay and extending between a port in a top portion ofthe overlay and the bottom opening to assist in the application ofreduced pressure to the area of the wound and removal of exudate fromthe wound; and the flexible overlay collapses in the approximatedirection of the area of the wound to be treated when reduced pressureis supplied to the volume under the flexible overlay in the area of thewound, such collapse causing the formation of an approximately hermeticseal between the flexible overlay and the body in the area of the wound;and a vacuum system, wherein the vacuum system comprises a reducedpressure supply source that provides a supply of reduced pressure; andreduced pressure supply means to operably connect the flexible overlayto the reduced pressure supply source, so that the volume under theflexible overlay in the area of the wound is supplied with reducedpressure by the reduced pressure supply source.
 15. The appliance ofclaim 14, wherein the reduced pressure supply source comprises a vacuumpump.
 16. The appliance of claim 15, wherein the reduced pressure supplysource further comprises a control system for the vacuum pump, whereinthe control system controls the operation of the vacuum pump.
 17. Theappliance of claim 15, wherein: the reduced pressure supply sourcefurther comprises a filter operably positioned between the vacuum pumpand the reduced pressure supply means; and the filter prevents theventing of and contamination of the vacuum pump by micro-organismsaspirated from the wound or fluids aspirated from the wound or both. 18.The appliance of claim 15, wherein the vacuum pump comprises a portablevacuum pump.
 19. The appliance of claim 14, wherein the reduced pressuresupply means comprises flexible tubing.
 20. The appliance of claim 14,wherein the reduced pressure supply means comprises a collection systemthat is operably positioned between the flexible overlay and the reducedpressure supply source and the collection system comprises a containerto receive and hold fluid aspirated from the wound.
 21. The appliance ofclaim 20, wherein the collection system comprises pressure halting meansto halt the application of reduced pressure to the wound when the fluidin the container exceeds a predetermined amount.
 22. The appliance ofclaim 14, wherein the reduced pressure under the impermeable overlay inthe area of the wound is in the range from approximately 20 mm of Hgbelow atmospheric pressure to approximately 125 mm of Hg belowatmospheric pressure.
 23. The appliance of claim 14, wherein the reducedpressure is applied in a cyclic nature, the cyclic nature providingalternating time periods of application of reduced pressure and withoutapplication of reduced pressure.
 24. The appliance of claim 14, furthercomprising tissue protection means operably positioned between the bodyand the portion of the impermeable overlay adjacent to the body at thewound site, the tissue protection means being to protect and strengthenthe tissue of the body adjacent to the flexible overlay at the woundsite.
 25. The appliance of claim 14, wherein the at least one channelcomprises at least one raised portion disposed on the surface of theflexible overlay.
 26. An appliance for administering reduced pressuretreatment to a wound on a body, the appliance comprising: a woundtreatment device, wherein the wound treatment device comprises aflexible overlay sized to be placed over and enclose the area of thewound to be treated and adapted to maintain reduced pressure in the areaof the wound to be treated and a plurality of channels to assist in theapplication of reduced pressure to the area of the wound and removal ofexudate from the wound, the plurality of channels each having a tubularstructure; wherein the flexible overlay collapses in the approximatedirection of the area of the wound to be treated when reduced pressureis supplied to the volume under the flexible overlay in the area of thewound and is configured to be sealed to the body in the area of thewound to maintain reduced pressure in the volume under the flexibleoverlay in the area of the wound to be treated.
 27. The appliance ofclaim 26, further comprising: a vacuum system, wherein the vacuum systemcomprises a suction bulb configured to provide a source of reducedpressure; and reduced pressure supply means to operably connect theflexible overlay to the suction bulb, so that the volume under theflexible overlay in the area of the wound may be supplied with reducedpressure by the suction bulb; wherein the suction bulb comprises aninlet port and an outlet port, wherein the inlet port is operablyconnected to the reduced pressure supply means; and the vacuum systemfurther comprises an exhaust tubing member operably connected to theoutlet port.
 28. The appliance of claim 27, wherein the vacuum systemfurther comprises an exhaust control valve operably connected to theexhaust tubing member.
 29. The appliance of claim 27, wherein the vacuumsystem comprises a filter operably connected to the exhaust tubingmember, wherein the filter prevents the venting of micro-organismsaspirated from the wound or exudate aspirated from the wound, or both.30. The appliance of claim 27, wherein the vacuum system comprises asupplemental vacuum system that is operably connected to the exhausttubing member.
 31. The appliance of claim 14, further comprising a woundpacking means, wherein the wound packing means is positioned between thewound treatment device and a portion of the wound to be treated.
 32. Theappliance of claim 14, further comprising: a suction drain extendingfrom the reduced pressure supply means into the volume under theflexible overlay in the area of the wound; and suction drain connectingmeans to operably connect the reduced pressure supply means to thesuction drain so that the suction drain is in fluid communication withthe reduced pressure supply means and reduced pressure is supplied tothe volume under the flexible overlay in the area of the wound by meansof the suction drain.
 33. The appliance of claim 32, wherein the suctiondrain comprises a distal end portion and the distal end portion has atleast one perforation in the surface thereof
 34. The appliance of claim33, wherein the distal end portion of the suction drain is positionedwithin the interior volume of the wound packing means.
 35. The applianceof claim 31, wherein the wound packing means is selected from the groupconsisting of absorbent dressings, antiseptic dressings, nonadherentdressings, water dressings, and combinations of such dressings.
 36. Theappliance of claim 35, wherein the wound packing means is selected fromthe group consisting of gauze, cotton and combinations of gauze andcotton.
 37. The appliance of claim 31, wherein the wound packing meanscomprises an absorbable matrix adapted to encourage growth of the tissuein the area of the wound into the matrix.
 38. The appliance of claim 37,wherein the absorbable matrix comprises a collagen material.
 39. Amethod of treating a wound on a body, such method comprising:positioning a flexible overlay on the body over the area of the wound tobe treated, wherein the flexible overlay has an apex and an open-endedbase and is sized to be placed over and enclose the area of the wound tobe treated and adapted to maintain reduced pressure in the area of thewound to be treated; and the flexible overlay comprises preformedsuction assist means extending generally from the apex toward aperipheral edge of the base to assist in the application of reducedpressure to the area of the wound and removal of exudate from the wound;operably connecting the flexible overlay with a vacuum system forproducing reduced pressure in the volume under the flexible overlay inthe area of the wound to be treated; collapsing the flexible overlay inthe approximate direction of the wound when reduced pressure is suppliedto the volume under the flexible overlay in the area of the wound sothat an approximately hermetic seal is formed between the flexibleoverlay and the body in the area of the wound; and maintaining thereduced pressure until the area of the wound being treated hasprogressed toward a selected stage of healing.
 40. The method of claim39, further comprising the step of placing tissue protection means onthe tissue of the body that is to be approximately adjacent to theflexible overlay, such tissue protection means being to protect andstrengthen the tissue of the body adjacent to the flexible overlay atthe wound site, such step being performed prior to positioning theflexible overlay over the area of the wound to be treated.
 41. Themethod of claim 39, further comprising the step of placing wound packingmeans between the wound and the flexible overlay in the area of thewound to be treated, such step being performed prior to positioning theflexible overlay over the area of the wound to be treated.
 42. Themethod of claim 39, wherein the vacuum system comprises a suction bulband the step of operably connecting the flexible overlay with the vacuumsystem further comprises the step of squeezing the suction bulb toreduce its volume and then releasing the suction bulb, so that reducedpressure is produced in the volume under the flexible overlay in thearea of the wound.
 43. The method of claim 39, wherein the reducedpressure under the impermeable overlay in the area of the wound is inthe range from approximately 20 mm of Hg below atmospheric pressure toapproximately 125 mm of Hg below atmospheric pressure.
 44. The method ofclaim 39, wherein the reduced pressure is applied in a cyclic nature,the cyclic nature providing alternating time periods of application ofreduced pressure and without application of reduced pressure.
 45. Themethod of claim 39, wherein the suction assist means comprises at leastone channel disposed on the surface of the flexible overlay.
 46. Themethod of claim 1, wherein the flexible overlay comprises a port, andthe reduced pressure supply means is operably connected to one side ofthe port, and the plurality of channels are operably connected to theother side of the port.
 47. The method of claim 39, wherein the suctionassist means comprises at least one raised portion disposed on thesurface of the flexible overlay.
 48. An appliance for administeringreduced pressure treatment to a wound on a body, the appliancecomprising: a liquid impermeable flexible overlay that maintains shapeupon the application of reduced pressure, the overlay having an openingsized to be placed over and enclose the area of the wound to be treated,and being adapted to maintain reduced pressure in the volume under theflexible overlay in the area of the wound; a seal to operably seal theflexible overlay to the body in the area of the wound to be treated, sothat reduced pressure is maintained in the volume under the flexibleoverlay in the area of the wound; and reduced pressure supply means tooperably connect the flexible overlay to a reduced pressure supplysource that provides a supply of reduced pressure to the flexibleoverlay, so that the volume under the flexible overlay in the area ofthe wound to be treated is supplied with reduced pressure by the reducedpressure supply source; wherein: the flexible overlay collapses in theapproximate direction of the area of the wound to be treated whenreduced pressure is supplied to the volume under the flexible overlay inthe area of the wound and the portions of the flexible overlay adjacentto the opening form a substantially perpendicular angle with the body inthe area of the wound adjacent to the opening of the flexible overlay;and the overlay comprises at least one channel disposed on the surfaceof the overlay extending from the reduced pressure supply means at theapex of the overlay toward the opening to assist in the application ofreduced pressure to the area of the wound and removal of exudate fromthe wound.
 49. The appliance of claim 48, wherein the flexible overlaycomprises an interior surface facing the area of the wound to be treatedand the surface area of the interior surface is greater than the surfacearea of the portion of the body to be enclosed by the flexible overlay.50. The appliance of claim 48, wherein the flexible overlay comprises aport and the reduced pressure supply means is operably connected to theport.
 51. The appliance of claim 48, wherein: at least one fold forms inthe surface of the flexible overlay when the flexible overlay collapses;and fluids aspirated by the wound flow along the at least one fold tothe reduced pressure supply means and are removed from the flexibleoverlay by means of the reduced pressure supply means cooperating withthe reduced pressure supply source.
 52. The appliance of claim 48,further comprising: a suction drain extending from the reduced pressuresupply means into the volume under the overlay in the area of the wound;and suction drain connecting means to operably connect the reducedpressure supply means to the suction drain so that the suction drain isin fluid communication with the reduced pressure supply means andreduced pressure is supplied to the volume under the flexible overlay inthe area of the Wound by means of the suction drain.
 53. The applianceof claim 48, further comprising a reduced pressure supply sourceoperably connected to the reduced pressure supply means, wherein thereduced pressure supply source provides a supply of reduced pressure sothat the volume under the flexible overlay in the area of the wound issupplied with reduced pressure by the reduced pressure supply source.54. The appliance of claim 48, further comprising a collection chamberto receive and hold fluid aspirated from the wound; and collectionchamber attachment means to operably attach the collection chamber tothe flexible overlay, wherein reduced pressure and the fluid arepermitted to flow between the collection chamber and the volume of theflexible overlay in the area of the wound.
 55. The appliance of claim48, wherein the flexible overlay comprises a port, and the reducedpressure supply means is operably connected to one side of the port, andthe at least one channel is operably connected to the other side of theport.
 56. The appliance of claim 48, wherein the at least one channelcomprises at least one raised portion disposed on the surface of theflexible overlay.
 57. The appliance of claim 26, wherein at least onechannel comprises an elongate and raised structure on the surface of theflexible overlay.
 58. The appliance of claim 26, wherein each of theplurality of channels comprises stiffening members that make each of theplurality of channels stiffer than the other portions of the flexibleoverlay.
 59. The appliance of claim 26, further comprising reducedpressure supply means to operably connect the flexible overlay to asource of reduced pressure.
 60. The appliance of claim 26, furthercomprising a source of reduced pressure operably connected to theflexible overlay.
 61. The appliance of claim 1, further comprising oneor more perforations formed in at least one of the plurality ofpreformed channels.
 62. The appliance of claim 1, further comprisingfoam configured to be positioned over the wound under the flexibleoverlay.
 63. The appliance of claim 14, further comprising one or moreperforations formed in the at least one channel.
 64. The appliance ofclaim 26, wherein the overlay is liquid impermeable.
 65. The applianceof claim 26, wherein the plurality of channels extend generally from afirst opening formed at the apex the overlay toward a peripheral edge ofthe overlay.
 66. The appliance of claim 26, wherein the tubularstructure has one or more perforations formed therein.
 67. The method ofclaim 45, wherein the at least one channel comprises one or moreperforations formed therein.